A method for preparing a bio-resistive thin film and a method for preparing a top electrode

Abstract

The application discloses a preparation method of a biological resistance variable thin film, and specifically comprises the following steps: step 1, egg yolk liquid and deionized water are weighed according to a volume ratio of 1:(1-5), and the two are mixed and stirred until the egg yolk liquid is uniformly distributed to obtain egg yolk sol; step 2, an immersion pulling method is adopted, a fish mouth clamp is used to clamp one corner of a substrate at 20-25 DEG C by using a pulling machine, a pulling film equipment switch is actuated, and the substrate is pulled in the egg yolk sol at a speed of 13-15 mm / s, and the egg yolk thin film prepared by pulling is dried at 20-25 DEG C for 1-2 min, so that the biological resistance variable thin film is obtained. The application further discloses a method for preparing a top electrode of the biological resistance variable thin film.

Description

Technical Field

[0001] This invention belongs to the field of resistive switching material preparation technology, specifically relating to a method for preparing a bio-resistive switching thin film, and also to a method for preparing a top electrode from the bio-resistive switching thin film. Background Technology

[0002] Resistive Randomized Modular Memory (RRAM) can function as both a data storage device and a logic computing device, combining computation and storage. Its intrinsic physical phenomenon involves resistance switching caused by changes in the intrinsic structure of the resistive switching material under an external electric field—specifically, the transition between high-resistance and low-resistance states. These two stable states correspond to the "0" and "1" states in binary computer operations. Based on their switching behavior, RRAM can be classified into unipolar and bipolar switching modes. In unipolar mode, the electrodes are the same, while in bipolar mode, they are reversed. Many materials, such as metal oxides, solid electrolytes, and organic materials, can serve as resistive switching layer materials for RRAM. Some non-toxic, harmless, and biodegradable natural biomaterials also exhibit resistance switching effects. Natural biomaterials can effectively simplify manufacturing processes and reduce the manufacturing cost of organic storage devices. Proteins, in particular, have seen rapid development, with various protein-based resistive switching materials emerging, such as silk fibroin, ferritin, egg white protein, recombinant proteins, and keratin. These have all been proven to possess typical resistive switching performance and can be applied to the research and development of data storage electronic devices. However, practical applications are currently lacking. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a bio-resistive switching film, using egg yolks, which can be obtained from fresh eggs, as raw materials to realize the preparation of a bio-film resistive switching memory.

[0004] To achieve the above objectives, the technical solution adopted by this invention is: a method for preparing a bioresistive switching film, specifically implemented according to the following steps:

[0005] Step 1: Weigh the egg yolk liquid and deionized water according to a volume ratio of 1:(1-5), mix them together and stir until the egg yolk liquid is evenly distributed to obtain egg sol.

[0006] Step 2: Using the dip-coating method, at 20-25℃, use a lifting machine to clamp one corner of the substrate with a fish-mouth clamp, turn on the film-coating equipment switch, and lift the film in the egg yolk sol at a speed of 13-15mm / s. Dry the egg yolk film obtained by the lifting method at 20℃-25℃ for 1-2 minutes to obtain the bioresistive switching film.

[0007] As a preferred technical solution of the present invention, in step 1, both are heated at 20℃-25℃.

[0008] As a preferred embodiment of the present invention, in step 1, the mixing and stirring time is 2 min to 5 min.

[0009] As a preferred technical solution of the present invention, in step 2, a lifting machine is used at 20℃-25℃.

[0010] As a preferred embodiment of the present invention, in step 2, the drying time is 1 min to 2 min.

[0011] As a preferred technical solution of the present invention, it further includes step 3, which uses ultraviolet light to cure the bioresistive switching film obtained in step 2.

[0012] A second objective of this invention is to provide a method for fabricating a top electrode using a biomass resistive switching film, for use in fabricating a top electrode for a resistive switching memory.

[0013] The beneficial effects of this invention are: with the rapid development of proteins as a natural biomaterial, natural biomaterials can effectively simplify manufacturing processes and reduce the cost of organic storage devices. The method of this invention uses egg yolks obtained from fresh eggs to prepare protein resistive switching thin film devices. Furthermore, the use of ultraviolet light curing further improves the stability of the protein film microstructure and enhances its resistive switching performance. Attached Figure Description

[0014] Figure 1 The image shows the infrared spectrum of the egg film prepared in Example 1 of this invention.

[0015] Figure 2 This is an AFM image of the egg membrane prepared in Example 1 of the present invention.

[0016] Figure 3 This is a structural diagram of the egg-shaped thin-film resistive switching memory PET / ITO / egg yolk / Au device prepared in Example 1 of the present invention.

[0017] Figure 4 This is an AFM image of the macromolecular clusters formed by the egg film prepared in Example 2 of this invention after being induced by ultraviolet light.

[0018] Figure 5 This is a schematic diagram of the electrical performance test of the egg yolk thin-film resistive switching memory prepared in Example 2 of the present invention.

[0019] Figure 6 This is a resistive switching performance test diagram of the egg yolk bioresistive switching memory prepared on a silicon substrate in Example 2 of the present invention.

[0020] Figure 7This is a resistive switching performance test diagram of the egg yolk bioresistive switching memory prepared on a flexible substrate in Example 2 of the present invention.

[0021] Figure 8 This is a resistive switching performance test diagram of the egg yolk bioresistive switching memory prepared by ultraviolet light curing on a flexible substrate in Example 3 of the present invention. Detailed Implementation

[0022] Example 1

[0023] The present invention provides a method for preparing a bioresistive switching film, the specific steps of which are as follows:

[0024] Wash and dry the fresh eggshells, break the shells and separate the egg whites and yolks. Place the egg yolk liquid (A) in a beaker for later use. Use a pipette to draw 1 ml of the egg yolk liquid and add it to a weighing bottle. Then use a dropper to draw 5 ml of deionized water (B) and add it to the weighing bottle. Mix and stir at 25°C for 5 minutes until the egg yolk liquid is evenly distributed, thus obtaining an egg yolk sol.

[0025] The dip-coating method was employed at 25°C. Using a dipping machine, a corner of the substrate was clamped with a fish-mouth clamp, and the film-coating equipment was activated at a speed of 15 mm / s to pull the film from an egg yolk sol. The resulting egg yolk film was then dried at 20°C for 2 minutes to obtain the biological egg yolk resistive switching film. The microstructure of this biological egg yolk resistive switching film was examined using Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM).

[0026] like Figure 1 As shown, the chemical bonding of the egg yolk biofilm was measured and analyzed using FT-IR to study the chemical functional group information of the biofilm and explore the laws of electron transfer within the biomaterial. Figure 3 In the analysis of the spectral peaks of the egg yolk biofilm, the peaks were identified as follows: 2600–3100 cm⁻¹ -1 The peak at 1745 cm⁻¹ is a characteristic absorption peak for N-H stretching vibrations. -1 The peak at this point corresponds to the C=O stretching vibration, 900–1200 cm⁻¹. -1 The peak at 1696 cm⁻¹ represents both the C-O-O stretching vibration peak and the characteristic peak of the P-O-C symmetrical stretching vibration. -1 The characteristic absorption peak of the amide I band is at 1531 cm⁻¹. -1 The characteristic absorption peaks of the amide II band are at 1300 and 1241 cm⁻¹. -1 The characteristic absorption peak of amide III is located at 2600–3100 cm⁻¹. The infrared spectrum of free amino acids is in the range of 2600–3100 cm⁻¹. -1 It exhibits strong absorption of N-H stretching vibrations, in the range of 1600–1590 cm⁻¹. -1It exhibits strong C-O stretching vibration absorption; the glycoside contains C-O-O bonds, which bind... Figure 3 This indicates that fresh egg yolks contain free amino acids and glycosides, while the amino acid residues in proteins have excellent ion-binding capabilities. Under the influence of an external electric field, they help to form conductive filaments, causing the proteins to exhibit typical resistive switching phenomena.

[0027] like Figure 2 The image shown is a microscopic morphology image obtained using atomic force microscopy (AFM). The measured area is 2 × 2 μm. 2 The surface roughness fluctuation value is 17.08 nm. Egg yolk particles with a particle size of about 20-50 nm are uniformly distributed on the surface. The surface of the egg yolk membrane is uniform and smooth.

[0028] The present invention discloses a method for fabricating a top electrode from a bioresistive switching thin film, comprising the following steps: turning on the sputtering apparatus, placing the bioresistive switching thin film sample into a fixture and fixing it in place, and securing the mask plate; using an ion sputtering apparatus to sputter an Au bottom electrode onto the substrate for a sputtering time of 120 s, a sputtering current of 5 mA, and a vacuum level of 8 × 10⁻⁶ within the sputtering chamber. -2 The sputtered Au dot-shaped top electrode serves as the top electrode for the bio-resistive switching thin-film resistive switching memory. A complete PET / ITO / egg yolk / Au bio-egg yolk resistive switching thin-film resistive switching unit is thus fabricated. A schematic diagram of the device structure is shown below. Figure 3 As shown.

[0029] Example 2

[0030] The present invention provides a method for preparing a bioresistive switching film, the specific steps of which are as follows:

[0031] Wash and dry the fresh eggshells, break the shells and separate the egg whites and yolks. Place the egg yolk liquid (A) in a beaker for later use. Use a pipette to draw 1 ml of the egg yolk liquid and add it to a weighing bottle. Then use a dropper to draw 1 ml of deionized water (B) and add it to the weighing bottle. Mix and stir at 25°C for 1 minute until the egg yolk liquid is evenly distributed, thus obtaining an egg yolk sol.

[0032] A dip-coating method was used at room temperature (25℃) with a dip-coating machine. The substrate was clamped at one corner using a fish-mouth clamp, and the film-coating equipment was activated at a speed of 13 mm / s in egg yolk sol. The resulting egg yolk film was then dried at room temperature (20℃) for 2 minutes to obtain a biological egg yolk resistive switching film. This biological resistive switching film was then processed using ultraviolet (UV) curing. A UV curing lamp with a luminous efficacy of 300 lm / W, a power of 30 W, a voltage of 250 V, and a wavelength of 365 nm was used as the curing light source. The dip-coated biological film was irradiated under the UV curing lamp at a distance of 5.0 cm from the light source for 1 minute. The UV curing lamp was then turned off, and the sample was left in place for 1 minute. All samples underwent UV curing at room temperature.

[0033] The ultraviolet-cured biofilm was observed using atomic force microscopy (AFM), such as... Figure 5 The image shown is an atomic force microscope (AFM) image of the egg yolk film after light curing. The measured area is 2 × 2 μm. 2 The surface roughness fluctuation value was 4.84 nm. The egg yolk membrane surface exhibited large molecular clusters with a diameter of approximately 200 nm, indicating that more stable biomolecular clusters were formed after UV curing. Figure 2 Comparison of microscopic images of egg yolk membranes revealed that the roughness fluctuation value of the membrane decreased after UV curing, indicating that the surface quality of the membrane was improved and biomolecular clusters with a diameter of about 200 nm were formed.

[0034] The present invention discloses a method for preparing a top electrode from a bio-resistant switching thin film, comprising the following steps: turning on the sputtering apparatus, placing the bio-egg yolk resistive switching thin film sample into a fixture and fixing it in place, and securing the mask plate; using an ion sputtering apparatus to sputter an Au bottom electrode onto the substrate for a sputtering time of 150 s, a sputtering current of 5.5 mA, and a vacuum degree of 8 × 10⁻⁶ within the sputtering chamber. -2 The sputtered Au dot-shaped top electrode serves as the top electrode for the biological egg yolk resistive switching thin-film memory. A complete Si / Pt / egg yolk / Au biological egg yolk resistive switching unit is thus fabricated.

[0035] The electrical performance testing steps for this bio-resistive switching device unit are as follows: The prepared resistive switching memory is placed on the precision probe stage of the ferroelectric instrument. The top electrode of the device is connected to the positive voltage input probe, and the bottom electrode is connected to the negative input signal probe. The connection test method between the electrical testing instrument and the device is as follows: Figure 5 As shown, open the test program, select the current-voltage (IV) test mode, set the protection current to 1 mA, and click the start measurement button to test the volt-ampere scan curve (IV curve). Figure 6 The figure shows the current-voltage curve of this bio-resistive switching Si / Pt / egg yolk / Au device. It indicates that the device is a bipolar resistive switching memory, with both the forward and negative reversal voltages at 3.5V. The device operates stably; the high-resistivity state conforms to the Poul-Frankfurt effect conduction mechanism, while the low-resistivity state conforms to the ohmic conduction mechanism.

[0036] Example 3

[0037] The present invention provides a method for preparing a bioresistive switching film, the specific steps of which are as follows:

[0038] Wash and dry the fresh eggshells, break the shells and separate the egg whites and yolks. Place the egg yolk liquid (A) in a beaker for later use. Use a pipette to draw 1 ml of the egg yolk liquid and drop it into a weighing bottle. Then use a dropper to draw 3 ml of deionized water (B) and drop it into the weighing bottle. Mix and stir at 22°C for 3 minutes until the egg yolk liquid is evenly distributed, thus obtaining an egg yolk sol.

[0039] Using the dip-coating method, at room temperature (22℃), a lifting machine is used to clamp one corner of a PET flexible substrate coated with an ITO bottom electrode using a fish-mouth clamp. The film-coating equipment is switched on and the film is lifted in egg yolk sol at a speed of 14mm / s. The egg yolk film obtained by the lifting process is then dried at room temperature (22℃) for 1.5 minutes to obtain a biological egg yolk resistive switching film.

[0040] The present invention discloses a method for preparing a top electrode from a bio-resistant switching thin film, comprising the following steps: turning on the sputtering apparatus, placing the bio-egg yolk resistive switching thin film sample into a fixture and fixing it in place, and securing the mask plate; using an ion sputtering apparatus to sputter an Au bottom electrode onto the substrate, the sputtering time being 135 s, the sputtering current being 5.2 mA, and the vacuum degree within the sputtering chamber being 8 × 10⁻⁶. -2 The sputtered Au dot-shaped top electrode, measured in mbar, serves as the top electrode for the biological egg yolk resistive switching thin-film resistive switching memory. A complete biological egg yolk resistive switching thin-film resistive switching unit is thus fabricated.

[0041] The electrical performance testing steps for this bio-resistive switching device unit are as follows: The prepared resistive switching memory is placed on the precision probe stage of the ferroelectric instrument. The top electrode of the device is connected to the positive voltage input probe, and the bottom electrode is connected to the negative input signal probe. The connection test method between the electrical testing instrument and the device is as follows: Figure 5 As shown, open the test program, select the current-voltage (IV) test mode, set the protection current to 0.1 mA, and click the start measurement button to test the volt-ampere scan curve (IV curve). Figure 7The figure shows the current-voltage curve of this bio-resistive switching PET / ITO / egg yolk / Au flexible device. The figure indicates that the device is a bipolar resistive switching memory, with a forward reversal voltage of 2.5V and a negative reversal voltage of -2.0V. The device exhibits stable operation; the high-resistivity state conforms to the Schottky effect conduction mechanism, while the low-resistivity state conforms to the Ohmic conduction mechanism.

[0042] Example 4

[0043] The present invention provides a method for preparing a bioresistive switching film, the specific steps of which are as follows:

[0044] Wash and dry the fresh eggshells, break the shells and separate the egg whites and yolks. Place the egg yolk liquid (A) in a beaker for later use. Use a pipette to draw 1 ml of the egg yolk liquid and drop it into a weighing bottle. Then use a dropper to draw 3 ml of deionized water (B) and drop it into the weighing bottle. Mix and stir at 22°C for 3 minutes until the egg yolk liquid is evenly distributed, thus obtaining an egg yolk sol.

[0045] Using the dip-coating method, at room temperature (22℃), a lifting machine is used to clamp one corner of a PET flexible substrate coated with an ITO bottom electrode using a fish-mouth clamp. The film-coating equipment is switched on and the film is lifted in egg yolk sol at a speed of 14mm / s. The egg yolk film obtained by the lifting process is then dried at room temperature (22℃) for 1.5 minutes to obtain a biological egg yolk resistive switching film.

[0046] Biological egg resistive switching films were processed using ultraviolet (UV) curing. A UV curing lamp with a luminous efficacy of 300 lm / W, a power of 30 W, a voltage of 250 V, and a wavelength of 365 nm was used as the curing light source. The stretched film was irradiated under the UV curing lamp at a distance of 5.0 cm from the light source for 1 minute. The UV curing lamp was then turned off, and the sample was left in place for 2 minutes. All samples underwent UV curing at room temperature. After the waiting period, the next stage of processing could proceed.

[0047] The present invention discloses a method for preparing a top electrode from a bio-resistant switching thin film, comprising the following steps: turning on the sputtering apparatus, placing the bio-egg yolk resistive switching thin film sample into a fixture and fixing it in place, and securing the mask plate; using an ion sputtering apparatus to sputter an Au bottom electrode onto the substrate, the sputtering time being 135 s, the sputtering current being 5.2 mA, and the vacuum degree within the sputtering chamber being 8 × 10⁻⁶. -2 The sputtered Au dot-shaped top electrode, measured in mbar, serves as the top electrode for the biological egg yolk resistive switching thin-film resistive switching memory. A complete biological egg yolk resistive switching thin-film resistive switching unit is thus fabricated.

[0048] The electrical performance testing steps for this bio-resistive switching device unit are as follows: The prepared resistive switching memory is placed on the precision probe stage of the ferroelectric instrument. The top electrode of the device is connected to the positive voltage input probe, and the bottom electrode is connected to the negative input signal probe. The connection test method between the electrical testing instrument and the device is as follows: Figure 5 As shown, open the test program, select the current-voltage (IV) test mode, set the protection current to 1 mA, and click the start measurement button to test the volt-ampere scan curve (IV curve). Figure 8 The figure shows the current-voltage curve of this bio-resistive switching PET / ITO / egg yolk / Au flexible device. The figure indicates that the device is a bipolar resistive switching memory, with a forward reversal voltage of 1.0V and a negative reversal voltage of -1.0V. The device operates stably; the high-resistivity state conforms to the Schottky effect conduction mechanism, and the low-resistivity state conforms to the Ohmic conduction mechanism. Figure 7 Comparative analysis revealed that the use of ultraviolet light curing increased the resistance to high current in the egg yolk film and reduced the reverse operating voltage of the device, indicating that the ultraviolet light curing method is very effective in curing and improving the resistive switching performance of biological films.

Claims

1. A method for preparing a bioresistive switching film, characterized in that, The specific steps are as follows: Step 1: Weigh egg yolk liquid and deionized water in a volume ratio of 1:(1-5), mix them at 20℃-25℃ and stir for 2min-5min until the egg yolk liquid is evenly distributed to obtain egg sol. Step 2: Using the dip-coating method, a lifting machine is used at 20-25℃. The fish mouth clamp is used to clamp one corner of the substrate, and the film-coating equipment is switched on. The film is lifted in the egg yolk sol at a speed of 13-15 mm / s. The egg yolk film obtained by the lifting process is dried at 20℃-25℃ for 1-2 minutes to obtain the bioresistive switching film. Step 3: Use ultraviolet light to cure the bioresistive switching film obtained in step 2; In step 3, the UV curing lamp used for UV curing is the curing light source, with a luminous efficacy of 300 lm / W, a power of 30 W, a voltage of 90V-250V, and a wavelength of 365nm-370nm. Specifically, the bioresistive switching film obtained in step 3 is irradiated under the UV curing lamp, with the bioresistive switching film 5.0cm-7.5cm away from the light source, for an irradiation time of 1min-5min. After that, the power of the UV curing lamp is turned off, and the bioresistive switching film is placed in place and waited for 1min-2min.

2. A method for fabricating a resistive switching memory using the bioresistive switching thin film obtained according to claim 1, characterized in that, Turn on the sputtering instrument, place the bioresistive switching thin film sample into the fixture and fix it in place, and secure the mask. Use an ion sputtering instrument to sputter the Au bottom electrode onto the substrate. The sputtering time is 120-150 s, the sputtering current is 5 mA-5.5 mA, and the vacuum level in the sputtering chamber is 8 × 10⁻⁶. -2 mbar is sputtered to form Au dot-shaped top electrodes to obtain a resistive switching memory.

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