Preparation method and application for depositing hafnium zirconium oxide thin film material with high energy storage density on attached silicon

Abstract

The invention relates to the technical field of development of novel microelectronic materials, preparation of dielectric film materials and prototype dielectric devices, and particularly discloses a preparation method and application of a hafnium zirconium oxide thin film material with high energy storage density deposited on attached silicon. A bottom electrode, a dielectric film layer and a top electrode are sequentially sputtered and deposited on the surface of the substrate from bottom to top through a radio frequency magnetron sputtering method, the bottom electrode is an aluminum-doped zinc oxide film, the dielectric film layer is a hafnium zirconium oxide ferroelectric film, and the top electrode is a gold upper electrode thin layer. The method comprises the following steps: S1, processing a substrate; s2, depositing a bottom electrode layer on the surface of the substrate; s3, depositing a dielectric film layer on the bottom electrode layer; s4, depositing a top electrode on the dielectric film layer; and S5, performing a dielectric test. The film material can be directly deposited on a silicon substrate at medium and low temperatures, and the prepared dielectric film material is lead-free, environment-friendly, simple in component, easy in raw material obtaining and suitable for industrial popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical fields of the development of new microelectronic materials, the preparation of dielectric film materials, and prototype dielectric device technologies, and particularly relates to a preparation method and application of a hafnium zirconium oxide thin film material with a high energy storage density deposited on adherent silicon. Background Art

[0002] The traditional perovskite ferroelectric thin film materials are mainly the following three: lead zirconate titanate (Pb(Zr,Ti)O3), barium titanate (BaTiO3), and strontium bismuth tantalate (SrBi2Ta2O9). The development of these traditional perovskite ferroelectric materials has encountered bottlenecks so far and there are many problems, such as a relatively small band gap (E g is about 3 - 4 eV), resulting in a Schottky barrier between it and the electrode of only about 1 eV, which easily causes the phenomena of leakage current and electrical breakdown failure. To improve their electrical properties, it is often necessary to relatively increase the thickness of the thin film (the thickness is about 100 nm), but there are the following problems when the thin film is too thick: 1) It will hinder the miniaturization of the three-dimensional capacitor structure and reduce its storage density; 2) The bond energy between oxygen atoms and component metal atoms is weak, which will generate a large number of oxygen vacancies, leading to reliability problems related to oxygen vacancies, such as fatigue effect, imprint effect, and retention failure, etc.; 3) Many lead-containing ferroelectric materials, such as Pb(Zr,Ti)O3, although having good ferroelectric properties, will cause a series of environmental problems due to the toxicity of lead elements. In addition, problems such as the incompatibility of traditional ferroelectric materials with silicon-based semiconductor processes and the serious degradation of electrical properties at small sizes have greatly affected the service reliability of ferroelectric memories and become bottlenecks restricting the development of ferroelectric memories. Therefore, people are eager to find a new ferroelectric material that can be used in future ferroelectric memories to overcome these problems that need to be solved urgently.

[0003] A linear dielectric capacitor is an element formed by combining a traditional capacitor structure and a dielectric material with linear response characteristics. Its core feature is that the dielectric body shows a linear relationship under an applied external electric field, that is, the dielectric constant ε is proportional to the electric field strength E. Similar to traditional capacitors, but with the introduction of a linear dielectric material, its internal structure usually includes two conductive plates and a dielectric body layer, and the characteristics of the dielectric body directly affect the working parameters of the capacitor. When an external electric field acts on the dielectric body, the dielectric constant ε shows a linear change relationship with the electric field strength E, that is, ε = kE, where k is a proportionality constant. This characteristic enables the capacitor to have an adjustable response ability under different electric fields. In applications that require dynamic adjustment of the dielectric constant, such as intelligent circuits, adaptive systems, etc., the linear dielectric capacitor provides a flexible adjustment means. Due to the linear response characteristics of the dielectric body, the capacitor can still maintain relatively stable performance under extreme conditions such as temperature and humidity changes, which helps to improve the system reliability.

[0004] At present, the academic community is exploring the linear response characteristics of different dielectric materials to optimize the performance of capacitors. Some advanced materials, such as certain organic polymers or semiconductor materials, exhibit high linear coefficients and stability. Hafnium oxide (HfO2) is a material with a wide bandgap and high dielectric constant. It was first used to replace the gate insulator silicon dioxide (SiO2) in metal-oxide-semiconductor field-effect transistors (MOSFETs), thus properly solving the size limit problem in the development of the previous SiO2 / Si structure in MOSFETs. Therefore, it is of great significance to design a hafnium zirconium oxide thin film material with simple preparation, simple composition, low deposition temperature, and excellent energy storage performance. Summary of the Invention

[0005] The present invention aims to explore the field of high energy storage of hafnium zirconium oxide thin films. Specifically, it provides a preparation method and application of depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon. This method is a simple preparation method for an environmentally friendly lead-free hafnium zirconium oxide dielectric film material. This dielectric film material is deposited on a silicon substrate with aluminum-doped zinc oxide as the electrode. It is easy to prepare, has a simple composition, a relatively low deposition temperature, and does not require high-temperature annealing treatment. It has excellent energy storage performance and provides a very promising option for a new generation of energy storage dielectric film materials.

[0006] The present invention is implemented by the following technical solutions: A preparation method for depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon. A semiconductor single-crystal silicon wafer is used as the substrate, and a bottom electrode, a dielectric film layer, and a top electrode are sequentially sputtered and deposited on the surface of the substrate from bottom to top by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin layer of gold upper electrode. The aluminum-doped zinc oxide used as the bottom electrode has good conductivity.

[0007] Furthermore, it includes the following steps:

[0008] S1. Treat the substrate, specifically through the following steps:

[0009] S11. Clean and install the substrate; place the cleaned substrate in the sample holder of the magnetron sputtering chamber;

[0010] S12. Pump to vacuum; pump the pressure of the magnetron sputtering chamber to the background vacuum;

[0011] S13. Introduce gas; after pumping the pressure of the magnetron sputtering chamber to the background vacuum, introduce argon gas into the magnetron sputtering chamber;

[0012] S14. Heat up the substrate;

[0013] S2. Deposit the bottom electrode layer on the surface of the substrate;

[0014] S3. Deposit a dielectric film layer on the bottom electrode layer;

[0015] S4. Deposit a top electrode on the dielectric film layer;

[0016] S5. Conduct dielectric testing.

[0017] Further, when depositing the bottom electrode in step S2, the sputtering atmosphere is a mixed gas of argon and oxygen, the flow rate of argon is 30 - 80 sccm, the flow rate of oxygen is 5 - 25 sccm, the sputtering pressure is 0.1 - 1.2 Pa, the sputtering power is 40 - 70 W, the deposition time is 5 - 30 min, and the deposition temperature is 200 - 350 °C.

[0018] Further, when depositing the hafnium zirconium oxide dielectric film in step S3, the sputtering atmosphere is a mixed gas of argon and oxygen, the flow rate of argon is 30 - 100 sccm, the flow rate of oxygen is 5 - 25 sccm, the sputtering pressure is 0.1 - 1.5 Pa, the sputtering power is 60 - 180 W, the deposition temperature is 250 - 500 °C, and the deposition time is 10 - 35 min.

[0019] Further, when depositing the dielectric film layer in step S3, a hafnium zirconium oxide ceramic with 50% mol of zirconium element is used as the sputtering target. Under the sputtering atmosphere of step S2, the sputtering power is adjusted to 60 W - 180 W, the deposition temperature is raised to 250 °C - 500 °C, and a hafnium zirconium oxide film is sputter - deposited on the aluminum - doped zinc oxide electrode. The sputtering time is 10 min - 30 min; after the sputter deposition is completed, the deposited hafnium zirconium oxide dielectric film layer is subjected to a cooling treatment.

[0020] Further, after depositing the hafnium zirconium oxide dielectric film layer, the magnetron sputtering chamber is adjusted to an oxygen atmosphere, and the deposited hafnium zirconium oxide dielectric film layer is subjected to a cooling treatment under the oxygen atmosphere condition; the flow rate of the oxygen atmosphere is 15 - 60 sccm, the pressure in the magnetron sputtering chamber is 0.5 - 10 Pa, and it is cooled to below 150 °C at a cooling rate of 2 - 10 °C / min.

[0021] Further, when depositing the top electrode in step S4, a thin gold upper electrode layer is sputter - deposited on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 20 - 60 sccm, the sputtering pressure is 0.1 - 1 Pa, the sputtering power is 30 - 100 W, the deposition time is 30 - 90 s, and the deposition temperature is 25 - 150 °C.

[0022] Further, the length of the sputter - deposited thin gold upper electrode layer is 10 mm, the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 200 - 1000 nm, the thickness of the top electrode layer is 30 - 150 nm, and the thickness of the dielectric film layer is 10 nm - 50 nm.

[0023] Further, when cleaning and installing the substrate in step S11, ultrasonic cleaning is performed with absolute ethanol, followed by rinsing with deionized water, and then drying with high-purity nitrogen. After that, the cleaned substrate is placed in the sample holder of the magnetron sputtering chamber.

[0024] When evacuating in step S12, the mechanical pump and molecular pump of the magnetron sputtering instrument are started in sequence to evacuate the pressure of the magnetron sputtering chamber to the background vacuum.

[0025] In step S13, the argon gas flow rate is 40 sccm, and the gas pressure of the magnetron sputtering chamber is adjusted to 2.5 Pa.

[0026] In step S14, the substrate is heated to 200 °C - 400 °C, and the heating rate is 5 °C / min.

[0027] Application of the hafnium zirconium oxide thin film material obtained by the above method for preparing a hafnium zirconium oxide thin film material with high energy storage density deposited on silicon in microelectromechanical system devices.

[0028] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0029] 1. The hafnium zirconium oxide film material prepared by the present invention does not contain any toxic elements and has excellent energy storage performance. It is an environmentally friendly dielectric material that is expected to replace the current mainstream energy storage materials.

[0030] 2. In the present invention, the hafnium zirconium oxide film is directly deposited on a silicon substrate with an aluminum-doped zinc oxide buffer layer. The preparation process is simple, highly controllable, the material system components are simple, and all the required raw materials are commercially available, which is convenient for industrial promotion and large-scale application.

[0031] 3. The preparation temperature of the hafnium zirconium oxide film material provided by the present invention is not higher than 500 °C, and no high-temperature annealing treatment is required, effectively reducing the high-temperature cost and material cost when preparing the energy storage thin film, and at the same time facilitating the integration and industrial application of semiconductor devices.

[0032] 4. The radio frequency magnetron sputtering technology adopted by the present invention is a physical vapor deposition technology, which has good compatibility with the current semiconductor microelectronics integration process and is particularly suitable for preparing large-size, high-quality, uniform and dense film materials. Description of the Drawings

[0033] Figure 1 It is a diagram showing the energy storage capacity of the hafnium zirconium oxide film material prepared in Example 3 of the present invention;

[0034] Figure 2 It is a diagram showing the polarization hysteresis loop of the hafnium zirconium oxide film material prepared in Example 3 of the present invention;

[0035] Figure 3XRD scan pattern of the hafnium zirconium oxide film prepared in Example 3 of the present invention;

[0036] Figure 4 TEM and EDS energy spectrum diagrams of the hafnium zirconium oxide film prepared in Example 3 of the present invention;

[0037] Figure 5 Transmission electron microscope image of the hafnium zirconium oxide film material prepared in Example 3 of the present invention. Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in conjunction with the appended Figures 1-5 drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0039] Example 1

[0040] A preparation method for depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon uses a semiconductor single crystal silicon wafer as a substrate, and sequentially sputters and deposits a bottom electrode, a dielectric film layer, and a top electrode on the surface of the substrate from bottom to top by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a gold upper electrode thin layer. The length of the sputtered gold upper electrode thin layer is 10 mm, and the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 200 nm, the thickness of the top electrode layer is 30 nm, and the thickness of the dielectric film layer is 10 nm.

[0041] The preparation method includes the following steps:

[0042] S1. Treat the substrate, specifically through the following steps:

[0043] S11. Clean and install the substrate. Ultrasonically clean it with anhydrous ethanol, then rinse it with deionized water, and then dry it with high-purity nitrogen. After that, put the cleaned substrate into the sample holder of the magnetron sputtering chamber.

[0044] S12. Evacuate. When evacuating, sequentially start the mechanical pump and molecular pump of the magnetron sputtering instrument, and evacuate the pressure of the magnetron sputtering chamber to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0045] S13. Introduce gas. After evacuating the pressure of the magnetron sputtering chamber to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and the air pressure of the magnetron sputtering chamber is adjusted to 2.5 Pa.

[0046] S14. Heat the substrate to 200 °C at a heating rate of 5 °C / min.

[0047] S2. Deposit a bottom electrode layer on the surface of the substrate. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 30 sccm, the flow rate of oxygen is 5 sccm, the sputtering pressure is 0.1 Pa, the sputtering power is 40 W, and the deposition time is 5 min. Among them, aluminum-doped zinc oxide is used as a buffer layer and a conductive layer, and the deposition temperature is 200 °C.

[0048] S3. Deposit a dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 30 sccm, the flow rate of oxygen is 5 sccm, the sputtering pressure is 0.1 Pa, the sputtering power is 60 W, the deposition temperature is 250 °C, and the deposition time is 10 min.

[0049] When depositing the dielectric film layer, hafnium zirconium oxide (Hf 0.5 Zr 0.5 O2) ceramic with 50% mol of zirconium element is used as the sputtering target. Under the sputtering atmosphere of step S2, the sputtering power is adjusted to 60 W, the deposition temperature is raised to 250 °C, and the hafnium zirconium oxide film is sputter-deposited on the aluminum-doped zinc oxide electrode. The sputtering time is 10 min. After the sputter deposition is completed, the deposited hafnium zirconium oxide dielectric film layer is cooled.

[0050] Adjust the magnetron sputtering chamber to an oxygen atmosphere, and cool the deposited hafnium zirconium oxide dielectric film layer under the oxygen atmosphere condition. The flow rate of the oxygen atmosphere is 15 sccm, the pressure of the magnetron sputtering chamber is 0.5 Pa, and it is cooled to below 150 °C at a cooling rate of 2 °C / min.

[0051] S4. Deposit a top electrode on the dielectric film layer. When depositing the top electrode, a thin gold upper electrode layer is sputter-deposited on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 20 sccm, the sputtering pressure is 0.1 Pa, the sputtering power is 30 W, the deposition time is 30 s, the deposition temperature is 25 °C, and the sample is taken out after sputtering.

[0052] S5. Conduct dielectric testing. Place the hafnium zirconium oxide film material with the thin gold top electrode obtained in step S4 on a ferroelectric hysteresis loop tester for testing.

[0053] Through performance testing, the hafnium zirconium oxide dielectric film material prepared in this embodiment has excellent performance. The hafnium zirconium oxide thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0054] Example 2

[0055] A preparation method of a hafnium zirconium oxide thin film material with high energy storage density deposited on adherent silicon uses a semiconductor single crystal silicon wafer as a substrate, and sequentially sputters and deposits a bottom electrode, a dielectric film layer, and a top electrode on the surface of the substrate from bottom to top by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin layer of gold upper electrode. The length of the sputtered and deposited thin layer of gold upper electrode is 10 mm, and the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 400 nm, the thickness of the top electrode layer is 60 nm, and the thickness of the dielectric film layer is 20 nm.

[0056] The preparation method includes the following steps:

[0057] S1. Treat the substrate, and specifically treat it through the following steps:

[0058] S11. Clean and install the substrate. Use anhydrous ethanol for ultrasonic cleaning, then rinse with deionized water, and then dry with high-purity nitrogen. After that, put the cleaned substrate into the sample holder in the magnetron sputtering chamber.

[0059] S12. Evacuate. When evacuating, sequentially start the mechanical pump and molecular pump of the magnetron sputtering instrument, and pump the pressure in the magnetron sputtering chamber to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0060] S13. Pass gas. After pumping the pressure in the magnetron sputtering chamber to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and adjust the air pressure in the magnetron sputtering chamber to 2.5 Pa.

[0061] S14. Heat up the substrate to 250 °C at a heating rate of 5 °C / min.

[0062] S2. Deposit a bottom electrode layer on the surface of the substrate. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 40 sccm, the flow rate of oxygen is 10 sccm, the sputtering pressure is 0.3 Pa, the sputtering power is 48 W, the deposition time is 10 min, and the deposition temperature is 230 °C.

[0063] S3. Deposit a dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 40 sccm, the flow rate of oxygen is 10 sccm, the sputtering pressure is 0.4 Pa, the sputtering power is 80 W, the deposition temperature is 300 °C, and the deposition time is 15 min.

[0064] When depositing the dielectric film layer, a hafnium zirconium oxide ceramic with 50% mol of zirconium element is used as the sputtering target. Under the sputtering atmosphere in step S2, the sputtering power is adjusted to 80 W, the deposition temperature is raised to 300 °C, and a hafnium zirconium oxide film is sputter-deposited on the aluminum-doped zinc oxide electrode. The sputtering time is 14 min. After the sputtering deposition is completed, the deposited hafnium zirconium oxide dielectric film layer is cooled down.

[0065] Adjust the magnetron sputtering chamber to an oxygen atmosphere, and cool down the deposited hafnium zirconium oxide dielectric film layer under the oxygen atmosphere conditions. The oxygen atmosphere flow rate is 28 sccm, the pressure in the magnetron sputtering chamber is 2 Pa, and it is cooled to below 150 °C at a cooling rate of 4 °C / min.

[0066] S4. Deposit the top electrode on the dielectric film layer. When depositing the top electrode, a thin gold upper electrode layer is sputter-deposited on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 30 sccm, the sputtering pressure is 0.2 Pa, the sputtering power is 50 W, the deposition time is 40 s, the deposition temperature is 45 °C, and the sample is taken out after the sputtering is completed.

[0067] S5. Conduct dielectric testing. Place the hafnium zirconium oxide film material with the thin gold upper electrode of the top electrode obtained in step S4 on a ferroelectric hysteresis loop tester for testing.

[0068] Through performance testing, the hafnium zirconium oxide dielectric film material prepared in this embodiment has excellent performance. The hafnium zirconium oxide thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0069] Example 3

[0070] A preparation method for depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon. A semiconductor single crystal silicon wafer is used as the substrate, and a bottom electrode, a dielectric film layer, and a top electrode are sequentially sputter-deposited from bottom to top on the substrate surface by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin gold upper electrode layer. The length of the sputter-deposited thin gold upper electrode layer is 10 mm, and the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 600 nm, the thickness of the top electrode layer is 90 nm, and the thickness of the dielectric film layer is 33 nm.

[0071] The preparation method includes the following steps:

[0072] S1. Treat the substrate, and the specific treatment steps are as follows:

[0073] S11. Clean and install the substrate. Ultrasonically clean the substrate with absolute ethanol, then rinse it with deionized water, and then dry it with high-purity nitrogen. After that, place the cleaned substrate in the sample holder of the magnetron sputtering chamber.

[0074] S12. Evacuate the chamber. When evacuating, start the mechanical pump and molecular pump of the magnetron sputtering instrument in sequence, and pump the pressure of the magnetron sputtering chamber down to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0075] S13. Introduce gas. After pumping the pressure of the magnetron sputtering chamber down to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and adjust the gas pressure of the magnetron sputtering chamber to 2.5 Pa.

[0076] S14. Heat up the substrate to 300 °C at a heating rate of 5 °C / min.

[0077] S2. Deposit the bottom electrode layer on the substrate surface. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 55 sccm, the flow rate of oxygen is 15 sccm, the sputtering gas pressure is 0.6 Pa, the sputtering power is 55 W, the deposition time is 15 min, and the deposition temperature is 270 °C.

[0078] S3. Deposit the dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 50 sccm, the flow rate of oxygen is 15 sccm, the sputtering gas pressure is 0.7 Pa, the sputtering power is 120 W, the deposition temperature is 350 °C, and the deposition time is 20 min.

[0079] When depositing the dielectric film layer, use hafnium zirconium oxide ceramic with 50% mol of zirconium element as the sputtering target. Under the sputtering atmosphere in step S2, adjust the sputtering power to 120 W, raise the deposition temperature to 350 °C, sputter-deposit the hafnium zirconium oxide film on the aluminum-doped zinc oxide electrode, and the sputtering time is 18 min. After the sputtering deposition is completed, cool down the deposited hafnium zirconium oxide dielectric film layer.

[0080] Adjust the magnetron sputtering chamber to an oxygen atmosphere, and cool down the deposited hafnium zirconium oxide dielectric film layer under the oxygen atmosphere condition. The flow rate of the oxygen atmosphere is 40 sccm, the gas pressure of the magnetron sputtering chamber is 4 Pa, and cool it down to below 150 °C at a cooling rate of 5 °C / min.

[0081] S4. Deposit the top electrode on the dielectric film layer. When depositing the top electrode, sputter-deposit a thin layer of gold top electrode on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 40 sccm, the sputtering pressure is 0.4 Pa, the sputtering power is 60 W, the deposition time is 60 s, the deposition temperature is 70 °C. After sputtering, take out the sample.

[0082] S5. Conduct dielectric testing. Place the hafnium zirconium oxide film material with the thin layer of gold top electrode obtained in step S4 on a ferroelectric hysteresis loop tester for testing.

[0083] The hafnium zirconium oxide thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0084] After performance testing, the hafnium zirconium oxide dielectric film material prepared in this embodiment has excellent performance. Figure 1 It is the ferroelectric hysteresis loop of the obtained hafnium zirconium oxide film material. The thickness is about 33 nm, showing a high recoverable energy storage density. It is calculated that Wrec = 37.45 J / cm3. Figure 2 Show the ferroelectric hysteresis loops of the obtained hafnium zirconium oxide film at different frequencies, having a large polarization intensity (>10 μC / cm2) and a high breakdown voltage resistance (≥20 V), showing good frequency stability. Figure 3 It is the XRD pattern of the hafnium zirconium oxide film material. The obtained hafnium zirconium oxide film material grows along the (111) orientation and has good crystallinity without any impurity phases. Figure 4 It is the scanning electron microscope image and energy spectrum analysis image of the surface of the obtained hafnium zirconium oxide film. The surface of the prepared thin film is flat, the grains are uniform and dense. Energy spectrum analysis shows that the atomic ratio of Hf:Zr:O is 1:1:2, which conforms to the stoichiometric ratio of hafnium zirconium oxide. Figure 5 It is the cross-sectional transmission electron microscope image of the hafnium zirconium oxide film. The thickness of the aluminum-doped zinc oxide electrode layer is 1 μm, and the thickness of the hafnium zirconium oxide film layer is 33 nm.

[0085] Example 4

[0086] A preparation method for depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon. Use a semiconductor single crystal silicon wafer as the substrate, and sequentially sputter-deposit a bottom electrode, a dielectric film layer, and a top electrode on the surface of the substrate from bottom to top by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin layer of gold top electrode. The length of the sputter-deposited thin layer of gold top electrode is 10 mm, the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 800 nm, the thickness of the top electrode layer is 120 nm, and the thickness of the dielectric film layer is 40 nm.

[0087] The preparation method includes the following steps:

[0088] S1. Process the substrate, specifically through the following steps:

[0089] S11. Clean and install the substrate. Ultrasonically clean the substrate with absolute ethanol, then rinse it with deionized water, and then dry it with high-purity nitrogen. After that, place the cleaned substrate in the sample holder of the magnetron sputtering chamber.

[0090] S12. Evacuate the chamber. When evacuating, start the mechanical pump and molecular pump of the magnetron sputtering instrument in sequence, and pump the pressure of the magnetron sputtering chamber to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0091] S13. Introduce gas. After pumping the pressure of the magnetron sputtering chamber to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and adjust the gas pressure of the magnetron sputtering chamber to 2.5 Pa.

[0092] S14. Heat up the substrate to 350 °C at a heating rate of 5 °C / min.

[0093] S2. Deposit the bottom electrode layer on the substrate surface. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 65 sccm, the flow rate of oxygen is 20 sccm, the sputtering gas pressure is 0.9 Pa, the sputtering power is 62 W, the deposition time is 25 min, and the deposition temperature is 300 °C.

[0094] S3. Deposit the dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 60 sccm, the flow rate of oxygen is 18 sccm, the sputtering gas pressure is 1 Pa, the sputtering power is 140 W, the deposition temperature is 400 °C, and the deposition time is 25 min.

[0095] When depositing the dielectric film layer, use hafnium zirconium oxide ceramic with 50% mol of zirconium element as the sputtering target. Under the sputtering atmosphere of step S2, adjust the sputtering power to 140 W, raise the deposition temperature to 400 °C, sputter and deposit the hafnium zirconium oxide film on the aluminum-doped zinc oxide electrode, and the sputtering time is 23 min. After the sputtering deposition is completed, cool down the deposited hafnium zirconium oxide dielectric film layer.

[0096] Adjust the magnetron sputtering chamber to an oxygen atmosphere, and cool down the deposited hafnium zirconium oxide dielectric film layer under the oxygen atmosphere condition. The flow rate of the oxygen atmosphere is 48 sccm, the gas pressure of the magnetron sputtering chamber is 6 Pa, and cool it to below 150 °C at a cooling rate of 6 °C / min.

[0097] S4. Deposit the top electrode on the dielectric film layer. When depositing the top electrode, sputter-deposit a thin layer of gold top electrode on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 48 sccm, the sputtering pressure is 0.6 Pa, the sputtering power is 70 W, the deposition time is 70 s, the deposition temperature is 100 °C, and the sample is taken out after sputtering is completed.

[0098] S5. Conduct dielectric testing. Place the hafnium zirconium oxide film material with the thin layer of gold top electrode obtained in step S4 on a ferroelectric hysteresis loop tester for testing.

[0099] Through performance testing, the hafnium zirconium oxide dielectric film material prepared in this embodiment has excellent performance. The hafnium zirconium oxide thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0100] Example 5

[0101] A preparation method for depositing a hafnium zirconium oxide thin film material with high energy storage density on attached silicon uses a semiconductor single crystal silicon wafer as a substrate, and sequentially sputter-deposits a bottom electrode, a dielectric film layer, and a top electrode from bottom to top on the surface of the substrate by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin layer of gold top electrode. The length of the sputter-deposited thin layer of gold top electrode is 10 mm, and the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 900 nm, the thickness of the top electrode layer is 130 nm, and the thickness of the dielectric film layer is 45 nm.

[0102] The preparation method includes the following steps:

[0103] S1. Treat the substrate, and specifically treat it through the following steps:

[0104] S11. Clean and install the substrate. Perform ultrasonic cleaning with anhydrous ethanol, then rinse with deionized water, and then dry with high-purity nitrogen. After that, place the cleaned substrate in the sample holder of the magnetron sputtering chamber.

[0105] S12. Evacuate. When evacuating, sequentially start the mechanical pump and molecular pump of the magnetron sputtering instrument, and pump the pressure of the magnetron sputtering chamber to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0106] S13. Introduce gas. After pumping the pressure of the magnetron sputtering chamber to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and the pressure of the magnetron sputtering chamber is adjusted to 2.5 Pa.

[0107] S14. Heat the substrate to 380 °C at a heating rate of 5 °C / min.

[0108] S2. Deposit a bottom electrode layer on the substrate surface. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 70 sccm, the flow rate of oxygen is 22 sccm, the sputtering pressure is 1 Pa, the sputtering power is 67 W, the deposition time is 28 min, and the deposition temperature is 320 °C.

[0109] S3. Deposit a dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 80 sccm, the flow rate of oxygen is 23 sccm, the sputtering pressure is 1.2 Pa, the sputtering power is 160 W, the deposition temperature is 450 °C, and the deposition time is 30 min.

[0110] When depositing the dielectric film layer, use a hafnium zirconium oxide ceramic with 50% mol of zirconium element as the sputtering target. Under the sputtering atmosphere of step S2, adjust the sputtering power to 160 W, raise the deposition temperature to 450 °C, sputter-deposit a hafnium zirconium oxide film on the aluminum-doped zinc oxide electrode, and the sputtering time is 27 min. After the sputtering deposition is completed, cool down the deposited hafnium zirconium oxide dielectric film layer.

[0111] Adjust the magnetron sputtering chamber to an oxygen atmosphere, and cool down the deposited hafnium zirconium oxide dielectric film layer under the oxygen atmosphere conditions. The flow rate of the oxygen atmosphere is 55 sccm, the pressure of the magnetron sputtering chamber is 8 Pa, and it is cooled to below 150 °C at a cooling rate of 8 °C / min.

[0112] S4. Deposit a top electrode on the dielectric film layer. When depositing the top electrode, sputter-deposit a thin gold upper electrode layer on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon, the flow rate is 55 sccm, the sputtering pressure is 0.8 Pa, the sputtering power is 90 W, the deposition time is 80 s, the deposition temperature is 120 °C, and the sample is taken out after the sputtering is completed.

[0113] S5. Conduct dielectric testing. Place the hafnium zirconium oxide film material with the thin gold top electrode obtained in step S4 on a ferroelectric hysteresis loop tester for testing.

[0114] After performance testing, the hafnium zirconium oxide dielectric film material prepared in this embodiment has excellent performance. The hafnium zirconium oxide thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0115] Example 6

[0116] A preparation method for depositing a hafnium zirconium oxide thin film material with a high energy storage density on adherent silicon uses a semiconductor single crystal silicon wafer as a substrate, and sequentially sputters and deposits a bottom electrode, a dielectric film layer, and a top electrode on the surface of the substrate from bottom to top by radio frequency magnetron sputtering. Among them, the bottom electrode is an aluminum-doped zinc oxide thin film, the dielectric film layer is a hafnium zirconium oxide ferroelectric thin film, and the top electrode is a thin gold upper electrode layer. The length of the sputtered thin gold upper electrode layer is 10 mm, and the width is 10 mm; the length of the substrate is 10 mm, the width is 10 mm, and the thickness is 0.5 mm; the thickness of the bottom electrode layer is 1000 nm, the thickness of the top electrode layer is 150 nm, and the thickness of the dielectric film layer is 50 nm.

[0117] The preparation method includes the following steps:

[0118] S1. Treat the substrate, and specifically treat it through the following steps:

[0119] S11. Clean and install the substrate. Use anhydrous ethanol for ultrasonic cleaning, then rinse with deionized water, and then dry with high-purity nitrogen. After that, place the cleaned substrate in the sample holder of the magnetron sputtering chamber.

[0120] S12. Evacuate. When evacuating, sequentially start the mechanical pump and molecular pump of the magnetron sputtering instrument, and pump the pressure of the magnetron sputtering chamber to the background vacuum (2×10 -4 Pa) to ensure the uniformity and density of the piezoelectric film material.

[0121] S13. Introduce gas. After pumping the pressure of the magnetron sputtering chamber to the background vacuum, introduce argon into the magnetron sputtering chamber. The flow rate of argon is 40 sccm, and adjust the air pressure of the magnetron sputtering chamber to 2.5 Pa.

[0122] S14. Heat up the substrate to 400 °C at a heating rate of 5 °C / min.

[0123] S2. Deposit the bottom electrode layer on the surface of the substrate. When depositing the bottom electrode, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 80 sccm, the flow rate of oxygen is 25 sccm, the sputtering pressure is 1.2 Pa, the sputtering power is 70 W, the deposition time is 30 min, and the deposition temperature is 350 °C.

[0124] S3. Deposit the dielectric film layer on the bottom electrode layer. When depositing the hafnium zirconium oxide dielectric film, the sputtering atmosphere is a mixed gas of argon and oxygen. The flow rate of argon is 100 sccm, the flow rate of oxygen is 25 sccm, the sputtering pressure is 1.5 Pa, the sputtering power is 180 W, the deposition temperature is 500 °C, and the deposition time is 35 min.

[0125] When depositing the dielectric film layer, a hafnium-zirconium-oxygen ceramic with 50% mol of zirconium element is used as the sputtering target. Under the sputtering atmosphere in step S2, the sputtering power is adjusted to 180 W, the deposition temperature is raised to 500 °C, and a hafnium-zirconium-oxygen film is sputter-deposited on the aluminum-doped zinc oxide electrode. The sputtering time is 30 min. After the sputter deposition is completed, the deposited hafnium-zirconium-oxygen dielectric film layer is subjected to a cooling treatment.

[0126] The magnetron sputtering chamber is adjusted to an oxygen atmosphere, and the deposited hafnium-zirconium-oxygen dielectric film layer is cooled under the condition of the oxygen atmosphere. The oxygen atmosphere flow rate is 60 sccm, the magnetron sputtering chamber pressure is 10 Pa, and it is cooled to below 150 °C at a cooling rate of 10 °C / min.

[0127] S4. Deposit the top electrode on the dielectric film layer. When depositing the top electrode, a thin gold top electrode layer is sputter-deposited on the surface of the deposited hafnium-zirconium-oxygen dielectric film layer. The sputtering atmosphere is argon, the flow rate is 60 sccm, the sputtering pressure is 1 Pa, the sputtering power is 100 W, the deposition time is 90 s, and the deposition temperature is 150 °C.

[0128] S5. Conduct dielectric testing. The hafnium-zirconium-oxygen film material with the thin gold top electrode obtained in step S4 is placed on a ferroelectric hysteresis loop tester for testing.

[0129] Through performance testing, the hafnium-zirconium-oxygen dielectric film material prepared in this embodiment has excellent performance. The hafnium-zirconium-oxygen thin film material prepared by the preparation method in this embodiment has great application potential in the field of microelectromechanical system devices.

[0130] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon, characterized in that: A semiconductor single crystal silicon wafer is used as a substrate, and a bottom electrode, a dielectric film layer, and a top electrode are sequentially sputtered and deposited on the substrate surface from bottom to top by a radio frequency magnetron sputtering method; wherein the bottom electrode is an aluminum-doped zinc oxide film, the dielectric film layer is a hafnium zirconium oxide ferroelectric film, and the top electrode is a gold top electrode thin layer.

2. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 1, characterized in that: The steps include: S1. Processing the substrate, specifically through the following steps: S11, cleaning and installing the substrate; placing the cleaned substrate into a sample holder of a magnetron sputtering chamber; S12, evacuating the chamber to a vacuum; evacuating the pressure of the magnetron sputtering chamber to a back-end vacuum; S13, passing gas; after the pressure of the magnetron sputtering chamber is evacuated to the back vacuum, argon gas is passed into the magnetron sputtering chamber; S14, heating the substrate to increase the temperature; S2, depositing a bottom electrode layer on the substrate surface; S3, depositing a dielectric film layer on the bottom electrode layer; S4, depositing a top electrode on the dielectric film layer; S5. Perform dielectric testing.

3. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 2, characterized in that: When depositing the bottom electrode in step S2, the sputtering atmosphere is a mixture of argon and oxygen, the argon flow rate is 30-80 sccm, the oxygen flow rate is 5-25 sccm, the sputtering pressure is 0.1-1.2 Pa, the sputtering power is 40-70 W, the deposition time is 5-30 min, and the deposition temperature is 200-350°C.

4. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 2, characterized in that: The sputtering atmosphere when depositing the hafnium zirconium oxide dielectric film in step S3 is a mixed gas of argon and oxygen, the argon flow rate is 30-100 sccm, the oxygen flow rate is 5-25 sccm, the sputtering pressure is 0.1-1.5 Pa, the sputtering power is 60-180 W, the deposition temperature is 250-500° C., and the deposition time is 10-35 min.

5. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 4, characterized in that: When depositing the dielectric film layer in step S3, a hafnium zirconium oxide ceramic containing 50 mol% of zirconium element is used as a sputtering target. Under the sputtering atmosphere of step S2, the sputtering power is adjusted to 60W to 180W, the deposition temperature is increased to 250°C to 500°C, and the hafnium zirconium oxide film is sputtered and deposited on the aluminum-doped zinc oxide electrode for a sputtering time of 10min to 30min. After the sputtering deposition is completed, the deposited hafnium zirconium oxide dielectric film layer is cooled.

6. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 5, characterized in that: After the hafnium zirconium oxide dielectric film layer is deposited, the magnetron sputtering chamber is adjusted to an oxygen atmosphere, and the deposited hafnium zirconium oxide dielectric film layer is cooled under oxygen atmosphere conditions; the oxygen atmosphere flow rate is 15 to 60 sccm, the magnetron sputtering chamber pressure is 0.5 to 10 Pa, and the temperature is cooled to below 150°C at a cooling rate of 2 to 10°C / min.

7. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 2, characterized in that: When depositing the top electrode in step S4, a thin layer of gold upper electrode is sputtered on the surface of the deposited hafnium zirconium oxide dielectric film layer. The sputtering atmosphere is argon gas, the flow rate is 20-60 sccm, the sputtering pressure is 0.1-1 Pa, the sputtering power is 30-100 W, the deposition time is 30-90 s, and the deposition temperature is 25-150°C.

8. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 1, characterized in that: The sputtering deposited gold upper electrode thin layer has a length of 10 mm and a width of 10 mm; the substrate has a length of 10 mm, a width of 10 mm and a thickness of 0.5 mm; the thickness of the bottom electrode layer is 200 to 1000 nm, the thickness of the top electrode layer is 30 to 150 nm, and the thickness of the dielectric film layer is 10 nm to 50 nm.

9. The method for preparing a hafnium zirconium oxide thin film material having a high energy storage density deposited on attached silicon according to claim 2, characterized in that: When cleaning and installing the substrate in step S11, anhydrous ethanol is used for ultrasonic cleaning, then it is rinsed with deionized water, and then it is blown dry with high-purity nitrogen gas, and then the cleaned substrate is placed in the sample holder of the magnetron sputtering chamber; When evacuating the vacuum in step S12, the mechanical pump and the molecular pump of the magnetron sputtering instrument are started in sequence to evacuate the pressure of the magnetron sputtering chamber to a back vacuum; In step S13, the flow rate of argon gas introduced is 40 sccm, and the gas pressure of the magnetron sputtering chamber is adjusted to 2.5 Pa; In step S14, the substrate is heated to 200° C. to 400° C. at a heating rate of 5° C. / min.

10. Use of the hafnium zirconium oxide thin film material obtained by the preparation method of hafnium zirconium oxide thin film material with high energy storage density deposited on attached silicon according to any one of claims 1 to 9 in micro-electromechanical system devices.

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