Transparent conductive oxide and preparation method thereof
By forming a mixture film layer of transparent conductive material and doped material on the substrate, etching to form a porous structure, the problem of high refractive index of transparent conductive film in the prior art is solved, and transparency with low refractive index and low resistivity is achieved The preparation of the conductive film layer is suitable for mass production and reduces costs.
Patent Information
- Application Number
- CN202411225567.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2024-12-13
AI Technical Summary
The prior art is difficult to prepare films with low refractive index and low resistivity under the conditions of guaranteeing reasonable costs and process. Common methods lead to product refractive index above 1.6, which cannot meet the requirements of low refractive index, and the process is complicated and difficult. Mass production.
By forming a mixture film layer of transparent conductive material and doped material on the substrate, the doped material is etched to form a porous transparent conductive film layer, with a pore size between 10 nm and 100 nm and a density between 10% and 50%. The acid or fluorine-containing dry etching gas is used to adjust the refractive index, combined with ultrasonic surface cleaning and medium-low temperature drying, to obtain transparent conductive oxides with low refractive index.
The production of a transparent conductive film layer with a dense structure and a low refractive index is realized, and it does not require modification equipment, is efficient and cheap, and is suitable for mass production.
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Figure CN119132700A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a transparent conductive oxide and a preparation method thereof. Background Art
[0002] Transparent conductive film (TCO film) is a material with high transparency and conductivity. It is widely used in display screens, solar energy, gas sensors, electrode materials for optoelectronic components and other fields. One of the main technical difficulties is how to prepare a film with high transmittance (in most cases considering the visible light wave domain) but low resistivity while ensuring a reasonable cost (thickness, chemical composition, equipment and process selection).
[0003] Common methods for adjusting the refractive index or density of TCO films are: 1) changing the roughness of the substrate; 2) adjusting the coating process parameters; 3) liquid phase non-vacuum coating such as sol-gel method; 4) oblique angle vacuum sputtering. Microporous loose structures can also be obtained by laser local opening, light shield coating, vacuum dry etching and other methods to change the density of the film, and finally obtain TCO materials that match the other film structures of the device. However, although these methods can obtain dense structures, the refractive index of the obtained products is generally above 1.6, which cannot meet the requirements of lower refractive index; if the low refractive index requirements are to be met, the coating equipment needs to be modified, or a complex production process is used, which is costly and difficult to convert to mass production. Summary of the invention
[0004] The purpose of the embodiments of the present application is to provide a transparent conductive oxide and a preparation method thereof, which can achieve the purpose of dense structure and low refractive index, and the preparation method is simple and convenient for mass production.
[0005] In one aspect of an embodiment of the present application, a method for preparing a transparent conductive oxide is provided, comprising forming a mixture film layer of a transparent conductive material and a doping material on a substrate;
[0006] The doping material is etched to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm, and the density is between 10% and 50%.
[0007] Optionally, forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises:
[0008] The transparent conductive material and the doping material are mixed in a ratio of 1:5 to 5:1; the doping material at least includes silicon dioxide and aluminum oxide.
[0009] Optionally, the thickness of the mixture film layer is between 50nm and 500nm.
[0010] Optionally, forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises:
[0011] The transparent conductive material and the doping material are co-sputtered on the substrate, and a coating speed of the co-sputtering of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0012] Optionally, forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises:
[0013] The transparent conductive material and the doping material are deposited on the substrate by atomic layer deposition, and the number of cycles of the gaseous state of the transparent conductive material and the gaseous state of the doping material passing into the vacuum chamber before the reaction is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0014] Optionally, forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises:
[0015] The transparent conductive material and the doping material are deposited on the substrate by chemical vapor deposition, and at least one of the coating time ratio, gas flow rate or coating power of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0016] Optionally, the etching of the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm, and the density is between 10% and 50%, comprises:
[0017] The doping material includes silicon dioxide or aluminum oxide;
[0018] Silicon dioxide etching acid or aluminum oxide etching acid is used to etch the mixture film layer, the etching temperature is between 20°C and 150°C, the etching selectivity of the etching solution to the doped material and the transparent conductive material is greater than 10:1, and the porous transparent conductive film layer is left after etching.
[0019] Optionally, the etching of the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm, and the density is between 10% and 50%, comprises:
[0020] The doping material includes silicon dioxide or aluminum oxide;
[0021] A fluorine-containing dry etching gas is selected to etch the mixture film layer, the etching temperature is between 20°C and 150°C, the etching selectivity of the etching gas to the doping material and the transparent conductive material is greater than 10:1, and the porous transparent conductive film layer is left after etching.
[0022] Optionally, after etching the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm and the density is between 10% and 50%, the method further comprises:
[0023] Ultrasonic surface cleaning to remove residual solid particles and etching liquid or etching gas on the surface of the transparent conductive film layer;
[0024] The transparent conductive oxide is obtained by drying at a medium to low temperature of 40° C. to 120° C. using a centrifuge.
[0025] Another aspect of the embodiments of the present application provides a transparent conductive oxide, which is prepared using the above-mentioned method for preparing the transparent conductive oxide.
[0026] The transparent conductive oxide and preparation method thereof provided in the embodiment of the present application, when the transparent conductive material and the doping material form a mixture film layer, they are presented in the form of a compound, the ions of the transparent conductive material are located in the gaps of the ions of the doping material, and the ions of the doping material are located in the gaps of the ions of the transparent conductive material, and the ions of the transparent conductive material and the ions of the doping material are diffused and filled to form a mixture film layer. The doping material is etched away, leaving the transparent conductive material, so that gaps are formed at the original position of the doping material, and a loose and porous transparent conductive material is obtained. In this way, a transparent conductive film layer with a low refractive index can be obtained without modifying the equipment hardware, which is efficient and low-cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0028] Figure 1 is a schematic diagram of the structure of the mixture film layer prepared in this embodiment;
[0029] Figure 2 It is a schematic diagram of the structure of the transparent conductive film layer prepared in this embodiment.
[0030] Icons: 10 - substrate; 11 - mixture film layer; 12 - transparent conductive film layer; 110 - ions of transparent conductive material; 111 - ions of doped material. DETAILED DESCRIPTION
[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.
[0032] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0033] It should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0034] The present invention provides a method for preparing a transparent conductive oxide, comprising:
[0035] Reference Figure 1 As shown, S100: forming a mixture film layer 11 of a transparent conductive material and a doping material on a substrate 10.
[0036] When the transparent conductive material and the doping material form a mixture film layer 11, they are in the form of a compound. The ions 110 of the transparent conductive material are located in the gaps between the ions 111 of the doping material, and the ions 111 of the doping material are located in the gaps between the ions 110 of the transparent conductive material. The mixture film layer 11 is formed by mutual diffusion and filling of the ions 110 of the transparent conductive material and the ions 111 of the doping material.
[0037] Generally speaking, the selected doping material needs to react with acid so that the doping material can be etched with acid to leave the transparent conductive material. In this way, gaps are formed at the original position of the doping material to obtain a loose and porous transparent conductive material. In this way, a transparent conductive film layer 12 with a low refractive index can be obtained.
[0038] The pore size in the transparent conductive film layer 12 is between 10 nm and 100 nm, and the density is between 10% and 50%.
[0039] In addition, due to operational limitations and errors, the doped material cannot be completely etched, and a small amount of doped material will remain in the original position. In this way, when the refractive index of the doped material is close to the refractive index of the transparent conductive material, a transparent conductive oxide with an overall low refractive index can be obtained, thereby avoiding the situation where the refractive index of the transparent conductive film layer 12 is increased by using a high refractive index doped material.
[0040] Specifically, a small amount of unetched doping material can allow the transparent conductive film layer 12 to retain electrical properties, while the transparent conductive material allows the transparent conductive film layer 12 to retain optical properties; therefore, in order to ensure the optical and electrical properties of the transparent conductive film layer 12, the transparent conductive material and the doping material can be mixed in a ratio of 1:5 to 5:1; the doping material includes at least silicon dioxide and aluminum oxide, and this application takes silicon dioxide as the doping material as an example for explanation.
[0041] When mixing the transparent conductive material and the doping material, the coating process can be adjusted by physical vapor deposition, atomic layer deposition, chemical vapor deposition, sputtering, etc., and the adjusted material is deposited or sputtered on the substrate 10 to form a mixture film layer 11.
[0042] For example, when the co-sputtering process is adopted, the transparent conductive material and the doping material are co-sputtered on the substrate 10, and the co-sputtering coating speed of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0043] When the atomic layer deposition process is adopted, the transparent conductive material and the doping material are deposited on the substrate 10 by atomic layer deposition, and the number of cycles of the gaseous transparent conductive material and the gaseous doping material passing into the vacuum chamber before the reaction is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0044] When the chemical vapor deposition process is adopted, the transparent conductive material and the doping material are deposited on the substrate 10 by chemical vapor deposition, and at least one of the coating time ratio, gas flow rate or coating power of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:1.
[0045] The substrate 10 includes a glass, crystalline silicon, sapphire, plastic or other material substrate 10, and the mixture film layer 11 formed on the substrate 10 is between 50nm and 500nm.
[0046] Reference Figure 2 As shown, S110: etching the doping material to leave a porous transparent conductive film layer 12 (TCO film layer) to form a transparent conductive oxide, wherein the pore size in the transparent conductive film layer 12 is between 10 nm and 100 nm, and the density is between 10% and 50%.
[0047] The doping material is etched by acid, including liquid acid etching and gas acid etching.
[0048] Doping materials include silicon dioxide or aluminum oxide;
[0049] When liquid acid etching is selected, silicon dioxide etching acid or aluminum oxide etching acid is used to etch the mixture film layer 11, the etching temperature is between 20°C and 150°C, the etching selectivity of the etching solution to the doped material and the transparent conductive material is greater than 10:1, and a porous transparent conductive film layer 12 is left after etching.
[0050] Since the etching solution will also etch the transparent conductive material, the etching selectivity (SiO 2 The higher the etching rate ratio between SiO and TCO, the better. 2 The speed of etching TCO is fast, and the speed of etching TCO is slow, which can ensure that SiO is etched as much as possible. 2 , preserve TCO.
[0051] For example, choose SiO 2 The etching solution, such as diluted hydrofluoric acid, sodium carbonate or sodium hydride, selectively etches the SiO 2 The material is etched to leave a porous transparent conductive film layer 12, forming a transparent conductive oxide.
[0052] When gas acid etching is used, a fluorine-containing dry etching gas is used to etch the mixture film layer 11. The etching temperature is between 20°C and 150°C. The etching selectivity of the etching gas to the doped material and the transparent conductive material is greater than 10:1. After etching, a porous transparent conductive film layer 12 is left.
[0053] After etching, a loose and porous TCO film is left, and the refractive index of the TCO film is reduced. The amount and size of the porosity of the TCO film affect its refractive index, which can be expressed as TCO / SiO 2 Proportional adjustment.
[0054] S120: Ultrasonic surface cleaning to remove solid particles and etching liquid or etching gas remaining on the surface of the transparent conductive film layer 12;
[0055] The transparent conductive oxide is obtained by drying at a medium to low temperature of 40° C. to 120° C. using a centrifuge.
[0056] Therefore, the preparation method of the transparent conductive oxide of the present application adopts a coating technology (evaporation, magnetron sputtering, chemical vapor deposition, or atomic layer deposition, etc.) combined with a wet or dry etching method to prepare a TCO film layer and achieve surface loosening (to obtain a low refractive index), without the need to modify the equipment hardware, and is efficient and low-cost.
[0057] The embodiments of the present application also disclose a transparent conductive oxide, which is prepared using any of the above methods for preparing a transparent conductive oxide.
[0058] The transparent conductive oxide comprises the same structure and beneficial effects as the preparation method of the transparent conductive oxide in the aforementioned embodiment. The structure and beneficial effects of the preparation method of the transparent conductive oxide have been described in detail in the aforementioned embodiment, and will not be repeated here.
[0059] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing a transparent conductive oxide, characterized in that: include: forming a mixture film layer of a transparent conductive material and a doping material on a substrate; The doping material is etched to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm, and the density is between 10% and 50%.
2. The method for preparing a transparent conductive oxide according to claim 1, characterized in that: The method of forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises: The transparent conductive material and the doping material are mixed in a ratio of 1:5 to 5:1; the doping material at least includes silicon dioxide and aluminum oxide.
3. The method for preparing a transparent conductive oxide according to claim 2, characterized in that: The thickness of the mixture film layer is between 50nm and 500nm.
4. The method for preparing a transparent conductive oxide according to claim 2, characterized in that: The method of forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises: The transparent conductive material and the doping material are co-sputtered on the substrate, and a coating speed of the co-sputtering of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:
1.
5. The method for preparing a transparent conductive oxide according to claim 2, characterized in that: The method of forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises: The transparent conductive material and the doping material are deposited on the substrate by atomic layer deposition, and the number of cycles of the gaseous state of the transparent conductive material and the gaseous state of the doping material passing into the vacuum chamber before the reaction is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:
1.
6. The method for preparing a transparent conductive oxide according to claim 2, characterized in that: The method of forming a mixture film layer of a transparent conductive material and a doping material on a substrate comprises: The transparent conductive material and the doping material are deposited on the substrate by chemical vapor deposition, and at least one of the coating time ratio, gas flow rate or coating power of the transparent conductive material and the doping material is adjusted so that the transparent conductive material and the doping material form a ratio of 1:5 to 5:
1.
7. The method for preparing a transparent conductive oxide according to any one of claims 1 to 6, characterized in that: The etching of the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10nm and 100nm, and the density is between 10% and 50%, comprises: The doping material includes silicon dioxide or aluminum oxide; Silicon dioxide etching acid or aluminum oxide etching acid is used to etch the mixture film layer, the etching temperature is between 20°C and 150°C, the etching selectivity of the etching solution to the doped material and the transparent conductive material is greater than 10:1, and the porous transparent conductive film layer is left after etching.
8. The method for preparing a transparent conductive oxide according to any one of claims 1 to 6, characterized in that: The etching of the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10nm and 100nm, and the density is between 10% and 50%, comprises: The doping material includes silicon dioxide or aluminum oxide; A fluorine-containing dry etching gas is selected to etch the mixture film layer, the etching temperature is between 20°C and 150°C, the etching selectivity of the etching gas to the doping material and the transparent conductive material is greater than 10:1, and the porous transparent conductive film layer is left after etching.
9. The method for preparing a transparent conductive oxide according to claim 1, characterized in that: After etching the doping material to leave a porous transparent conductive film layer to form the transparent conductive oxide, wherein the pore size in the transparent conductive film layer is between 10 nm and 100 nm and the density is between 10% and 50%, the method further comprises: Ultrasonic surface cleaning to remove residual solid particles and etching liquid or etching gas on the surface of the transparent conductive film layer; The transparent conductive oxide is obtained by drying at a medium to low temperature of 40° C. to 120° C. using a centrifuge.
10. A transparent conductive oxide, characterized in that: The transparent conductive oxide is prepared by the preparation method of any one of claims 1 to 9.