Preparation method of tungsten oxide film used in electronic component

Abstract

The invention discloses a preparation method of a tungsten oxide thin film used in an electronic component, and belongs to the technical field of thin film materials. The film is mainly prepared by using an ion beam deposition system. And feeding the substrate into an ion plating deposition system, and plating a tungsten oxide film in the process of changing the plating process parameters. The method is easy and convenient to operate and high in controllability, and the prepared film is stable in performance and completely meets the performance requirements of electronic components or electrochromic composite film layers and the like.

Description

Technical Field

[0001] This invention belongs to the field of thin film materials technology, specifically, it relates to a method for preparing tungsten oxide thin films used in electronic components. Background Technology

[0002] Thin film materials used in electronic components and electrochromic materials are divided into inorganic and organic materials. Inorganic materials have received widespread attention because they can meet the performance requirements of all film materials in electronic components and electrochromic materials, and also exhibit stable performance. In particular, the core film layer used in recent years—tungsten oxide film—has been the subject of extensive research, as its performance directly determines the overall performance of the devices used in them. Therefore, optimizing the performance of tungsten oxide film can effectively improve its application range in various fields.

[0003] In existing technologies, sol-gel and spray pyrolysis methods struggle to achieve precise control over the microstructure of thin films at the nanoscale, potentially resulting in films with high porosity, uneven density, and excessively wide grain size distribution. Chemical vapor deposition (CVD) often requires high-temperature environments or expensive vacuum equipment, increasing energy consumption and production costs while limiting its applicability to flexible substrates with poor heat resistance. Therefore, developing a novel, low-temperature, low-cost, high-performance tungsten oxide thin film process to overcome these shortcomings is crucial for its application in next-generation electronic components and advanced electrochromic devices. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing tungsten oxide thin films used in electronic components.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing a tungsten oxide thin film for use in electronic components includes the following processes: an ITO-coated glass substrate is fed into the chamber of an ion beam deposition system; after evacuating the chamber, high-purity argon gas (99.999% purity) is introduced to pre-sputter a tungsten target at a power of 250W, an argon flow rate of 20 sccm, and a pre-sputtering time of 15 min; subsequently, oxygen is introduced to purge the substrate; finally, in an atmosphere of argon and oxygen, tungsten oxide is deposited on the substrate surface by sputtering; after heat treatment, the finished tungsten oxide thin film is obtained.

[0006] The proposed solution employs the synergistic effect of pre-sputtering and oxygen pre-purging to simultaneously achieve three major objectives: removing and activating the target material, eliminating floating membrane structures on the ITO surface, and passivating existing membrane layers. Ultimately, this ensures the bonding effect of subsequent membrane layers.

[0007] Ideally, the sheet resistance of the ITO coated glass is 5-30Ω.

[0008] The optimal parameters for the sputtering process are: power 250-350W, argon flow rate 35sccm, and oxygen flow rate 15-25sccm.

[0009] Ideally, the heat treatment is carried out in an oxygen atmosphere at a temperature of 300°C for 2 hours.

[0010] Ideally, the thickness of the finished tungsten oxide film is 254-300 nm, and the average visible light transmittance is 57-62%.

[0011] The beneficial effects of this invention are: (1) This invention makes full use of the ion beam deposition system. The entire process flow is clear, involving only two gases, argon and oxygen, with few variable parameters, avoiding complex gas path systems and cumbersome process switching. This makes the process easy to control, adjust and repeat, which is conducive to obtaining tungsten oxide films with consistent performance and lays a good foundation for industrial production; (2) The unique pretreatment combination of "argon pre-sputtering followed immediately by oxygen purging" effectively removes oxides from the target surface, ensuring the purity and stability of the sputtering source. Furthermore, it effectively removes the floating film structure on the ITO substrate surface and passivates it, providing a clean, stable, and highly adhesive ideal interface for subsequent thin film deposition. Finally, combined with post-treatment heat treatment in an oxygen atmosphere, the microstructure of the thin film is further optimized. This synergistic effect ultimately produces a high-quality tungsten oxide thin film with strong adhesion, high density, stable performance, and fully meets the requirements for use in electronic components and electrochromic devices.

[0012] (3) The method of the present invention is specifically designed for the performance requirements of tungsten oxide thin films for electronic components (especially electrochromic devices). From the selection of the substrate (ITO glass with a specific resistance range), interface treatment to post-heat treatment, the entire process chain is designed to optimize the electrochemical performance and stability of the thin film. The prepared thin film can be directly applied to related devices and has high practical value and market prospects. Detailed Implementation

[0013] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0014] Example 1 High-purity (99.99%) tungsten (W) metal target was selected as the sputtering target material. The substrate was ITO coated glass with a sheet resistance of about 15Ω and an ITO film thickness of about 400nm. The substrate was subjected to strict ultrasonic cleaning before use to remove surface contaminants. The cleaned ITO glass substrate was fixed to the sample holder and placed into the vacuum chamber of the ion beam deposition system. The chamber was then closed, and the vacuum system was activated. The vacuum level inside the chamber reached 3.0 × 10⁻⁶. -6 When Pa is reached, proceed with subsequent operations; The ion beam deposition system was activated, and high-purity argon gas (99.999% purity) was introduced into the chamber via the gas supply system to pre-sputter the tungsten target. The power was 250W, the argon gas flow rate was 20 sccm, and the pre-sputtering time was 15 minutes. Pre-sputtering involved bombarding the tungsten target surface with argon ions. This step aimed to remove native oxides from the target surface and activate the target. After pre-sputtering, the argon gas supply was stopped, and oxygen was introduced instead. The oxygen flow was used to purge the ITO substrate surface. This operation effectively removed floating film structures bonded to the ITO surface and simultaneously passivated the substrate surface to enhance the adhesion of subsequent film layers. Finally, a mixture of argon and oxygen is introduced, and the following process parameters are set for reactive sputtering deposition: sputtering power: 250W, argon flow rate: 35sccm, oxygen flow rate: 15sccm, deposition time: 30min. During this process, argon ions continuously bombard the tungsten target, and the sputtered tungsten particles react with oxygen to generate tungsten oxide and deposit it on the substrate to form a tungsten oxide film. After the thin film deposition was completed, the sample was heat-treated at 300°C for 2 hours in a pure oxygen atmosphere. After the heat treatment was completed, the power and gas were turned off and the sample was allowed to cool naturally to room temperature in the furnace to obtain the finished tungsten oxide thin film with a thickness of 253 nm and an average visible light transmittance of 57%.

[0015] Example 2 High-purity (99.99%) tungsten (W) metal target was selected as the sputtering target material. The substrate was ITO coated glass with a sheet resistance of about 15Ω and an ITO film thickness of about 400nm. The substrate was subjected to strict ultrasonic cleaning before use to remove surface contaminants. The cleaned ITO glass substrate was fixed to the sample holder and placed into the vacuum chamber of the ion beam deposition system. The chamber was then closed, and the vacuum system was activated. The vacuum level inside the chamber reached 3.0 × 10⁻⁶. -6 When Pa is reached, proceed with subsequent operations; The ion beam deposition system was activated, and high-purity argon gas (99.999% purity) was introduced into the chamber via the gas supply system to pre-sputter the tungsten target. The power was 250W, the argon gas flow rate was 20 sccm, and the pre-sputtering time was 15 minutes. Pre-sputtering involved bombarding the tungsten target surface with argon ions. This step aimed to remove native oxides from the target surface and activate the target. After pre-sputtering, the argon gas supply was stopped, and oxygen was introduced instead. The oxygen flow was used to purge the ITO substrate surface. This operation effectively removed floating film structures bonded to the ITO surface and simultaneously passivated the substrate surface to enhance the adhesion of subsequent film layers. Finally, a mixture of argon and oxygen is introduced, and the following process parameters are set for reactive sputtering deposition: sputtering power: 300W, argon flow rate: 35sccm, oxygen flow rate: 20sccm, deposition time: 30min. During this process, argon ions continuously bombard the tungsten target, and the sputtered tungsten particles react with oxygen to generate tungsten oxide and deposit it on the substrate to form a tungsten oxide film. After the thin film deposition was completed, the sample was heat-treated at 300°C for 2 hours in a pure oxygen atmosphere. After the heat treatment was completed, the power and gas were turned off and the sample was allowed to cool naturally to room temperature in the furnace to obtain the finished tungsten oxide thin film with a thickness of 300 nm and an average visible light transmittance of 62%.

[0016] Example 3 High-purity (99.99%) tungsten (W) metal target was selected as the sputtering target material. The substrate was ITO coated glass with a sheet resistance of about 15Ω and an ITO film thickness of about 400nm. The substrate was subjected to strict ultrasonic cleaning before use to remove surface contaminants. The cleaned ITO glass substrate was fixed to the sample holder and placed into the vacuum chamber of the ion beam deposition system. The chamber was then closed, and the vacuum system was activated. The vacuum level inside the chamber reached 3.0 × 10⁻⁶. -6 When Pa is reached, proceed with subsequent operations; The ion beam deposition system was activated, and high-purity argon gas (99.999% purity) was introduced into the chamber via the gas supply system to pre-sputter the tungsten target. The power was 250W, the argon gas flow rate was 20 sccm, and the pre-sputtering time was 15 minutes. Pre-sputtering involved bombarding the tungsten target surface with argon ions. This step aimed to remove native oxides from the target surface and activate the target. After pre-sputtering, the argon gas supply was stopped, and oxygen was introduced instead. The oxygen flow was used to purge the ITO substrate surface. This operation effectively removed floating film structures bonded to the ITO surface and simultaneously passivated the substrate surface to enhance the adhesion of subsequent film layers. Finally, a mixture of argon and oxygen is introduced, and the following process parameters are set for reactive sputtering deposition: sputtering power: 350W, argon flow rate: 35sccm, oxygen flow rate: 25sccm, deposition time: 30min. During this process, argon ions continuously bombard the tungsten target, and the sputtered tungsten particles react with oxygen to generate tungsten oxide and deposit it on the substrate to form a tungsten oxide film. After the thin film deposition was completed, the sample was heat-treated at 300°C for 2 hours in a pure oxygen atmosphere. After the heat treatment was completed, the power and gas were turned off and the sample was allowed to cool naturally to room temperature in the furnace to obtain the finished tungsten oxide thin film with a thickness of 290 nm and an average visible light transmittance of 60%.

[0017] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0018] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing a tungsten oxide thin film for use in electronic components, characterized in that, The process includes the following steps: an ITO-coated glass substrate is fed into the chamber of an ion beam deposition system; after evacuating the chamber, high-purity argon gas is introduced to pre-sputter a tungsten target at a power of 250W, an argon flow rate of 20sccm, and a pre-sputtering time of 15min; subsequently, oxygen is introduced to purge the substrate; finally, in an atmosphere of mixed argon and oxygen, tungsten oxide film is deposited on the substrate surface by sputtering; after heat treatment, the finished tungsten oxide film is obtained.

2. The method for preparing a tungsten oxide thin film for use in electronic components according to claim 1, characterized in that, The sheet resistance of the ITO coated glass is 5-30Ω.

3. The method for preparing a tungsten oxide thin film for use in electronic components according to claim 1, characterized in that, The parameters of the sputtering process are: power 250-350W, argon flow rate 35sccm, and oxygen flow rate 15-25sccm.

4. The method for preparing a tungsten oxide thin film for use in electronic components according to claim 1, characterized in that, The heat treatment is carried out in an oxygen atmosphere at a temperature of 300°C for 2 hours.

5. The method for preparing a tungsten oxide thin film for use in electronic components according to claim 1, characterized in that, The finished tungsten oxide film has a thickness of 254-300 nm and an average visible light transmittance of 57-62%.