Spin coating device for applying in-situ electric field

Abstract

The invention relates to the technical field of spin-coating devices, and particularly discloses a spin-coating device for applying an in-situ electric field, which consists of a device main body, a rotating shaft, a sample support, a substrate, an air exhaust channel, an upper electrode plate, a lower electrode plate, a central controller, an oilless vacuum pump, an electric telescopic rod, a rubber gasket, a voltage-stabilizing direct-current power supply system, a sealing glass cover, a vent valve and a mechanical pump. A rotating shaft is vertically arranged in the center in the device body, the top of the rotating shaft is sleeved with a horizontally-arranged sample support, a substrate is placed on the sample support, an upper electrode plate and a lower electrode plate are arranged above and below the sample support respectively, and the upper electrode plate is connected with an electric telescopic rod and is in communication connection with a central controller to adjust the height. The upper electrode plate and the lower electrode plate are connected with a voltage-stabilizing direct-current power supply; the voltage-stabilizing direct-current power supply system comprises a voltage regulator, an alternating-current / direct-current converter and an alternating-current voltage frequency regulator, and is in communication connection with the central controller. And the sealing glass cover is connected with the ventilation valve and the mechanical pump, and is in communication connection with the central controller to carry out vacuum or atmosphere protection on the spin-coating device. According to the invention, any direct-current / alternating-current electric field can be applied in the solution spin-coating process, the atmosphere and air pressure can be adjusted, and the uniformity and compactness of the large-area ultrathin film are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of spin coating devices, and in particular relates to a spin coating device for applying an in-situ electric field. Background Art

[0002] Solution spin coating uses the centrifugal force generated by high-speed rotation to drive the viscous solution to diffuse outward and volatilize into a film. It has been widely used in semiconductor integrated circuits, solar cells, biomedicine and other fields.

[0003] At present, in the process of spin coating thin films by ordinary spin coaters, due to the influence of complex fluid mechanics (such as diffusion), surface physicochemical processes (such as wetting, viscosity, etc.) and the spin coating environment, the uniformity and density of the thin film are difficult to be effectively guaranteed, which limits the application of this method in modern information and energy storage devices. At present, in order to obtain uniform and dense ultra-thin films, researchers continue to optimize the spin coating process parameters, including spin coating speed, solution viscosity, spin coating time and temperature control during spin coating, etc., to adjust the thickness, porosity and crystallinity of the film. In addition, by applying additives such as surfactants, stabilizers and functional molecules, the morphology of the film can be regulated. Finally, by performing appropriate chemical or physical treatment on the film substrate, the adhesion between the film and the substrate and the uniformity during the spin coating process can be improved. However, even with the above scheme, when spin coating large-area ultra-thin films with a thickness of less than 50nm, it still tends to form non-continuous, non-uniform island-shaped films with bubble holes. Therefore, it is necessary to develop a new preparation platform to achieve the preparation of large-area uniform and dense ultra-thin films. Summary of the invention

[0004] The purpose of the present invention is to solve the disadvantage that a discontinuous, uneven island-shaped film with air bubbles and holes is easily formed when spin coating an ultra-thin film, and a spin coating device for applying an in-situ electric field is provided.

[0005] The present invention provides a spin coating device for applying an in-situ electric field, which consists of a device body, a rotating shaft, a sample holder, a substrate, an exhaust channel, an upper electrode plate, a lower electrode plate, a central controller, an oil-free vacuum pump, an electric telescopic rod, a rubber gasket, a voltage-stabilized DC power supply system, a sealed glass cover, a vent valve, and a mechanical pump; the voltage-stabilized DC power supply system includes a voltage regulator, an AC / DC converter, and an AC voltage frequency regulator.

[0006] The spin coating device for applying an in-situ electric field provided by the present invention has a rotating shaft arranged vertically in the center of the main body of the device, and a horizontally arranged sample holder is mounted on the top of the rotating shaft; a substrate is placed on the sample holder; the interior of the sample holder is a hollow cavity, and an adsorption hole connected to the substrate is arranged on the top surface of the sample holder. An exhaust channel is arranged along the axial direction of the rotating shaft center, and the exhaust channel is respectively connected to the sample holder and an oil-free vacuum pump; an upper electrode plate and a lower electrode plate are respectively arranged above and below the sample holder; the upper electrode plate is connected to an electric telescopic rod, and the electric telescopic rod is communicatively connected to a central controller, and the central controller can adjust the height of the electric telescopic rod; the upper electrode plate is connected to the lower electrode plate and a voltage-stabilized DC power supply system; the sealed glass cover is connected to a vent valve and a mechanical pump, and is communicatively connected to the central controller; the voltage-stabilized DC power supply system is communicatively connected to the central controller.

[0007] In the spin coating device for applying an in-situ electric field provided by the present invention, the oil-free vacuum pump absorbs the substrate placed on the sample holder through the exhaust channel when in operation.

[0008] In the spin coating device for applying an in-situ electric field provided by the present invention, a rubber gasket is placed between the sample holder and the lower electrode plate for vibration reduction.

[0009] The invention provides a spin coating device for applying an in-situ electric field, wherein the sealing glass cover performs vacuum or atmosphere protection on the spin coating device of the invention.

[0010] Compared with the existing spin coating technology, the beneficial effects of the present invention are:

[0011] 1. The present invention can apply an electric field to the sample holder through the upper and lower electrode plates while spin coating the thin film, and utilize the electrostatic interaction between the electric dipoles in the same polarity solution as the electric field and the synergistic coupling between the electric dipoles and the microstructure to promote a better and more orderly arrangement of the thin film material at different scales from atoms, nanodomains to microstructures during high-speed spin coating, thereby realizing the preparation of large-area homogeneous ultra-thin films or even single-crystal ultra-thin films.

[0012] 2. The present invention takes into account that the quality of the spin-coated film is closely related to the gas type, humidity or air pressure while applying the electric field in situ, and the air breakdown electric field also decreases significantly with increasing humidity. Therefore, the spin-coating device is in a sealed glass cover and can provide a dry protective atmosphere or a vacuum atmosphere, further improving the uniformity and density of large-area ultra-thin films. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1The present invention is a schematic structural diagram of a spin coating device for applying an in-situ electric field; wherein the device body 1, a rotating shaft 2, a sample holder 3, a substrate 4, an exhaust channel 5, an upper electrode plate 6, a lower electrode plate 7, a central controller 8, an oil-free vacuum pump 9, an electric telescopic rod 10, a rubber gasket 11, a voltage-stabilized DC power supply system 12, a sealing glass cover 13, a vent valve 14, a mechanical pump 15, a voltage regulator 121, an AC / DC converter 122, and an AC voltage frequency regulator 123;

[0014] Figure 2 A system diagram of a spin coating device for applying an in-situ electric field according to the present invention;

[0015] Figure 3 This is the surface morphology of polyvinylidene fluoride film;

[0016] Figure 4 This is the surface morphology of lead zirconate film. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0018] Embodiment 1:

[0019] The present invention will be described in detail below with reference to the accompanying drawings. Figure 1 As shown, a spin coating device for applying an in-situ electric field is composed of a device body 1, a rotating shaft 2, a sample holder 3, a substrate 4, an exhaust channel 5, an upper electrode plate 6, a lower electrode plate 7, a central controller 8, an oil-free vacuum pump 9, an electric telescopic rod 10, a rubber gasket 11, a stabilized DC power supply system 12, a sealing glass cover 13, a vent valve 14, and a mechanical pump 15.

[0020] A rotating shaft 2 is vertically arranged in the center of the device body 1, and a horizontally arranged sample holder 3 is mounted on the top of the rotating shaft 2; a substrate 4 is placed on the sample holder 3, the interior of the sample holder 3 is a hollow cavity, and an adsorption hole connected to the substrate 4 is arranged on the top surface; an exhaust channel 5 is arranged along the axial direction of the center of the rotating shaft 2, and the exhaust channel 5 is respectively connected to the sample holder 3 and the oil-free vacuum pump 9; when the substrate 4 is placed on the sample holder 3, the oil-free vacuum pump 9 is started, and the oil-free vacuum pump 9 evacuates the hollow cavity inside the sample holder 3, and adsorbs the substrate 4 on the sample holder 3 under the action of atmospheric pressure; an upper electrode plate 6 is arranged above the sample holder 3, and the upper electrode plate 6 is connected to an electric telescopic rod 10, and the electric telescopic rod 10 is communicatively connected to the central controller 8, and a lower electrode plate 7 is arranged below the sample holder 3, and a rubber gasket 11 is placed between the lower electrode plate 7 and the rotating shaft 2 for vibration reduction, and the upper electrode plate 6 and the lower electrode plate 7 are both connected to a stabilized DC power supply system 12. The voltage-stabilized power supply system includes a voltage regulator 121, an AC / DC converter 122 and an AC voltage frequency regulator 123, and is connected to the central controller 8 in communication; the sealed glass cover 13 is connected to the vent valve 14 and the mechanical pump 15, and is connected to the central controller 8 in communication. The sealed glass cover 13 performs vacuum or atmosphere protection on the spin coating device.

[0021] In this embodiment: the upper electrode plate 6 is connected to the electric telescopic rod 10, and the electric telescopic rod 10 is communicated with the central controller 8, and can be automatically raised and lowered by the central controller according to the set parameters to adjust the height between the upper electrode plate and the lower electrode plate.

[0022] In this embodiment: the upper electrode plate 6 and the lower electrode plate 7 are both connected to the voltage regulator 121 in the voltage-stabilized power supply system 12, and are communicated with the central controller 8, and the voltage value can be automatically adjusted by the central controller 8 according to the set parameters.

[0023] In this embodiment: the upper electrode plate 6 and the lower electrode plate 7 are both connected to the AC / DC converter 122 in the voltage-stabilized power supply system 12, can apply AC or DC voltage, and are connected to the central controller 8 for communication, and can automatically switch according to the settings.

[0024] In this embodiment: the upper electrode plate 6 and the lower electrode plate 7 are both connected to the AC voltage frequency regulator 123 in the voltage-stabilized power supply system 12, and are communicated with the central controller 8. Under the premise of setting the AC voltage, the voltage frequency is automatically adjusted by the central controller 8 according to the set parameters.

[0025] In this embodiment: the sealed glass cover 13 is connected to the ventilation valve 14 and the mechanical pump 15, and is in communication connection with the central controller 8. After turning on the mechanical pump 15, selecting the gas type through the ventilation valve 14 and setting the gas flow rate, the air pressure in the sealed glass cover is automatically adjusted by the central controller 8 according to the set parameters.

[0026] Example 2: Organic PVDF (polyvinylidene fluoride) spin coating morphology with in-situ electric field

[0027] Step 1: Solution preparation

[0028] With diethyl carbonate (C5H 10 O3) is used as solvent, polyvinylidene fluoride is used as solute, diethyl carbonate and polyvinylidene fluoride are reacted in a mass ratio of 0.99:0.01, heated and stirred at 70°C for 2 hours, and then cooled to room temperature to obtain a transparent solution.

[0029] Step 2: Preparation of thin film materials

[0030] (1) Using Au(111) / Cr / SiO2 / Si substrate, drop the solution prepared in step 1 onto the substrate for spin coating;

[0031] (2) The distance between the upper electrode plate and the lower electrode plate is adjusted by a telescopic rod, and an electric field of 10 kV / cm is applied in situ;

[0032] (3) The rotation speed was adjusted to 3000 rpm and the time was 30 seconds to obtain a dense PVDF organic film with a thickness of only 13 nanometers (see Figure 3 ).

[0033] Embodiment 3:

[0034] Step 1: Solution preparation

[0035] Use ethylene glycol methyl ether (2-MOE) as solvent, lead acetate (Pb(CH3COO)2·3H2O) and zirconium n-propoxide (Zr(OCH2CH2CH3)4) as solute. According to the atomic ratio of Pb:Zr of 1.1:1, weigh lead acetate and zirconium n-propoxide. Add ethylene glycol methyl ether to lead acetate at a concentration of 0.1M, distill at 120℃ for 2 hours, then cool to room temperature, add zirconium n-propoxide, and stir at room temperature for 2 hours. Finally, add ethylene glycol methyl ether again to supplement the solvent loss caused by the distillation process, so that the solution concentration reaches 0.1M, and a light yellow transparent lead zirconate solution is obtained;

[0036] Step 2: Preparation of thin film materials

[0037] (1) Using a Pt(111) / Ti / SiO2 / Si substrate, drop the lead zirconate solution prepared in step 1 onto the substrate for spin coating;

[0038] (2) The distance between the upper electrode plate and the lower electrode plate is adjusted by a telescopic rod, and an electric field of 5 kV / cm is applied in situ;

[0039] (3) rotating at a speed of 3000 rpm for 30 seconds to obtain a raw film;

[0040] (4) drying the raw film at 450° C. for 5 minutes to remove moisture and thermally decompose organic matter to obtain an amorphous film;

[0041] (5) The amorphous film is placed in a rapid annealing furnace and annealed at 650°C for 3 minutes to obtain the required lead zirconate thin film material. The film material has a thickness of about 50 nanometers and has a uniform and dense grain structure (see Figure 4 ).

[0042] Matters not covered in the present invention are known technologies. The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A spin coating device for applying an in-situ electric field, characterized in that: The device is composed of a device body (1), a rotating shaft (2), a sample holder (3), a substrate (4), an exhaust channel (5), an upper electrode plate (6), a lower electrode plate (7), a central controller (8), an oil-free vacuum pump (9), an electric telescopic rod (10), a rubber gasket (11), a voltage-stabilized DC power supply system (12), a sealing glass cover (13), a vent valve (14), and a mechanical pump (15); A rotating shaft (2) is vertically arranged in the center of the device body (1), and a horizontally arranged sample holder (3) is mounted on the top of the rotating shaft (2); A substrate (4) is placed on the sample holder (3); An air suction channel (5) is arranged at the center of the rotating shaft (2) along its axial direction, and the air suction channel (5) is respectively connected to the sample holder (3) and the oil-free vacuum pump (9); The sample holder (3) is provided with an upper electrode plate (6) and a lower electrode plate (7) respectively; The upper electrode plate (6) is connected to an electric telescopic rod (10), and the electric telescopic rod (10) is communicatively connected to a central controller (8); The upper electrode plate (6) is connected to the lower electrode plate (7) and a voltage-stabilized DC power supply system (12); The sealed glass cover (13) is connected to the ventilation valve (14) and the mechanical pump (15), and is in communication connection with the central controller (8); The voltage-stabilized DC power supply system (12) is communicatively connected to the central controller (8).

2. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: The interior of the sample holder (3) is a hollow cavity, and the top surface of the sample holder (3) is provided with an adsorption hole connected to the substrate (4).

3. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: The voltage-stabilized DC power supply system (12) comprises a voltage regulator (121), an AC / DC converter (122), and an AC voltage frequency regulator (123).

4. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: When the oil-free vacuum pump (9) is in operation, it adsorbs the substrate (4) placed on the sample holder (3) through the suction channel (5).

5. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: The central controller (8) can adjust the height of the electric telescopic rod (10).

6. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: A rubber gasket (11) is placed between the sample holder (3) and the lower electrode plate (7) for vibration reduction.

7. The spin coating device for applying an in-situ electric field according to claim 1, characterized in that: The sealed glass cover (13) provides vacuum or atmosphere protection for the spin coating device.

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