Integrated preparation device and method of large-size bdd electrode based on multi-zone coordinated thermal field regulation

Abstract

The application discloses a kind of based on multi-zone coordinated thermal field regulation and control large-size BDD electrode integrated preparation device and method, belong to CVD equipment technical field.The device includes reaction chamber, liftable base, multi-zone independent controllable hot wire system, composite temperature monitoring system and intelligent control system.It is in that hot wire system is divided into multiple independent temperature control subareas, and temperature measurement mode combining contact and non-contact is used, and the temperature of multiple regions on substrate surface is obtained in real time by control system, each subarea hot wire power is dynamically and independently adjusted by closed-loop control, accurate, active coordinated regulation and control of surface temperature field of large-size substrate is realized, and "edge effect" is effectively inhibited.The method can automatically prepare large-size BDD electrode, and the electrode has excellent in-plane uniformity in film thickness, doping concentration and oxygen evolution potential and other key performances.The application solves the problem of uniform preparation of large-size high-performance BDD electrode, and provides a reliable technical foundation for industrial mass production.

Description

Technical Field

[0001] This invention belongs to the field of chemical vapor deposition (CVD) equipment and electrode preparation technology, specifically relating to a hot filament chemical vapor deposition (HFCVD) apparatus and method for preparing large-size, high-performance boron-doped diamond (BDD) thin film electrodes, and particularly an integrated preparation system that achieves precise and coordinated control of the thermal field on the surface of large-size substrates through multi-zone independent temperature control. Background Technology

[0002] Advanced oxidation technologies are an effective means of treating high-salt, high-concentration, and recalcitrant organic wastewater, aiming to oxidize and decompose large organic molecules into smaller molecules or directly mineralize them. Among them, electrochemical advanced oxidation technology has attracted much attention due to its good environmental compatibility and ease of operation. Boron-doped diamond (BDD) electrodes are considered the best anode material in this field due to their extremely wide electrochemical window, extremely low background current, excellent physicochemical stability, and strong antifouling ability. Currently, the most economical and commonly used method for preparing BDD thin films is hot-filament chemical vapor deposition (HFCVD).

[0003] Domestic BDD electrode fabrication is mostly limited to laboratory research, resulting in small electrode sizes that cannot meet the demands of industrial applications. However, the core bottleneck in transitioning BDD electrodes from laboratory research to industrial application lies in the uniform and controllable fabrication of large-size, high-quality BDD films. Traditional HFCVD equipment faces significant challenges in this regard. (1) Poor thermal field uniformity: Traditional equipment often uses a simple and uniform array of hot wires (such as parallel arrangement), which generates a temperature field above the substrate with a significant "edge effect", that is, a huge temperature difference between the central region and the edge region. For large-size substrates, this effect is amplified sharply, resulting in inconsistencies in the growth rate, boron doping concentration, and grain orientation of diamond films at different locations on the substrate. As the size of the reaction chamber increases, it becomes difficult to maintain uniformity in the distance between the hot wire and the substrate, the flow rate of the reaction gas, and the temperature field, resulting in significant gradients in the thickness, boron doping concentration, and crystal quality of the deposited BDD film, affecting the consistency of electrode performance. This non-uniformity directly leads to huge differences in the electrochemical performance of the BDD electrode (such as oxygen evolution potential, background current, and charge transport resistance) at different locations on the electrode surface, making it unable to meet the stringent requirements of industrial-grade electrodes for uniformity, stability, and reliability.

[0004] (2) Insufficient temperature monitoring and control accuracy: In the large chamber, a single temperature measurement method (such as relying solely on the thermocouple on the back of the substrate) is insufficient to accurately and in real time reflect the true temperature of the substrate surface (especially different areas). Temperature is a decisive factor affecting diamond nucleation, growth, morphology, and boron doping efficiency. Inaccurate monitoring directly leads to inaccurate control, which in turn causes uneven stress distribution in the film, easily leading to film cracking, warping, or detachment, resulting in low yield.

[0005] (3) Low level of automation and poor process repeatability: The deposition process involves multiple complex steps such as vacuuming, preheating, aeration, deposition and cooling. It is highly dependent on the experience of operators. Manual control makes it difficult to ensure the accurate repeatability of process parameters, which seriously restricts the batch stability and large-scale mass production of products.

[0006] Therefore, developing a dedicated HFCVD device and method that can actively and precisely control the uniformity of the temperature field on the surface of large-size substrates and achieve fully automated control of the entire process has become the key to promoting the industrial application of BDD electrodes. Summary of the Invention

[0007] To address the aforementioned issues, the primary objective of this invention is to overcome the shortcomings of existing HFCVD technology in the fabrication of large-size BDD electrodes, such as uneven thermal field, low temperature control accuracy, and insufficient automation. The invention provides an integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field regulation. This device, through the design of a regionally independently controllable thermal field system, enables independent monitoring and precise, coordinated control of the temperature in different regions of the substrate surface, thereby forming a highly uniform and stable growth temperature field throughout the entire deposition area. This method offers advantages such as good temperature control uniformity, low contamination, precise temperature control, and high automation, enabling the fabrication of high-quality, highly repeatable large-size BDD electrodes.

[0008] Another objective of this invention is to provide a method for fabricating large-size, high-performance BDD electrodes using the aforementioned apparatus. This method exhibits good process repeatability, a high degree of automation, and can stably fabricate large-area BDD electrodes with uniform film thickness, consistent doping, excellent electrochemical performance, and high surface uniformity.

[0009] Another objective of this invention is to provide a large-size BDD electrode product prepared by the above method, which exhibits excellent in-plane uniformity in key performance parameters such as oxygen evolution potential and electrochemical active area.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: On the one hand, this invention proposes an integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control, including... Reaction chamber; A base plate disposed within the reaction chamber is used to support the substrate; A multi-zone independently controllable hot filament system is suspended above the base to provide the heat source required for deposition; the hot filament system is divided into at least three electrically independent hot filament zones whose heating power can be independently controlled. An independent power control unit is electrically connected to each of the aforementioned hot filament zones; A temperature monitoring system is used to monitor in real time the temperature of the substrate surface or near-surface on the substrate and the corresponding temperature of each of the hot wire sub-regions; the temperature monitoring system includes a contact temperature measurement unit and a non-contact temperature measurement unit; The control system has its signal input terminal connected to the temperature monitoring system and its control output terminal connected to each of the independent power control units. The control system is configured to: receive the temperature signal from the temperature monitoring system, calculate the characterization temperature of each zone on the substrate surface through an algorithm, and dynamically and independently adjust the heating power of each hot wire zone by comparing the characterization temperature with the preset target temperature of each zone, so as to achieve coordinated control of the thermal field on the substrate surface and make the temperature field on the substrate surface tend to be uniform.

[0011] The control system includes a programmable logic controller (PLC) and a human-machine interface (HMI), which stores preset process recipes and can realize fully automated operation from vacuuming, preheating, introducing reaction gas, deposition temperature control to cooling and sampling.

[0012] Furthermore, the hot wire partition includes a central region, a transition region surrounding the central region, and an edge region surrounding the transition region.

[0013] Furthermore, the hot wire arrangement density in the edge region is greater than that in the center region, and the average distance between the hot wire in the edge region and the substrate surface is less than or equal to the average distance between the hot wire in the center region and the substrate surface.

[0014] Furthermore, the contact temperature measurement unit is a plurality of thermocouple temperature monitoring units embedded inside the base and corresponding to the positions of each hot wire partition; the non-contact temperature measurement unit is one or more infrared temperature detection units that are aligned with each partition of the substrate surface through a viewing window set on the wall of the reaction chamber.

[0015] Furthermore, the base is a liftable design, connected to the bottom of the reaction chamber via a lifting mechanism to adjust the distance between the hot filament system and the substrate surface. The lifting mechanism is a conventional mechanism and will not be described in detail here.

[0016] Furthermore, the device also includes an external cabinet and a gas system, a vacuum system, and a water cooling system that are connected to the interior of the reaction chamber.

[0017] Secondly, the present invention proposes a method for fabricating large-size boron-doped diamond electrodes (BDD) using the apparatus described above, comprising the following steps: S1: Place a large-size substrate (such as a circular substrate with a diameter ≥ 150mm or a square substrate with a diameter of 250mm x 200mm) on the substrate platform; S2: Start the hot wire system and execute multi-zone coordinated thermal field regulation through the control system to heat the substrate surface to the deposition temperature and stabilize it at the preset target temperature value. The target temperature value set for the edge region of the substrate surface is higher than the target temperature value set for the center region of the substrate surface. S3: A reaction gas containing carbon source, hydrogen and boron dopant source is introduced into the reaction chamber through the gas path system, and a boron doped diamond film is deposited on the substrate under the control of the multi-zone synergistic thermal field. S4: After deposition, the reaction gas is stopped, and the material is cooled under controlled conditions to obtain the large-size boron-doped diamond electrode.

[0018] Furthermore, in step S2, the difference between the target temperature value of the edge region of the substrate surface and the target temperature value of the center region is 5°C to 30°C.

[0019] Furthermore, the control system continuously adjusts the heating power of each hot wire zone based on feedback from the temperature monitoring system, so that the temperature fluctuation range of each area on the substrate surface is controlled within ±5℃.

[0020] Furthermore, the thickness non-uniformity of the deposited boron-doped diamond film is less than 5%, and the boron doping concentration non-uniformity is less than 10%.

[0021] Thirdly, the present invention also proposes a large-size boron-doped diamond electrode, which is prepared by the method described above, wherein the oxygen evolution potential difference in different regions of the electrode surface is less than 0.1V and the electrochemical active area deviation is less than 5%.

[0022] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: (1) Extremely high thermal uniformity: By dividing the hot filament array into independently controllable zones and combining multi-zone temperature measurement and closed-loop feedback control, this invention can actively and accurately compensate for the inherent "edge effect" of large-size substrates, controlling the temperature non-uniformity of the substrate surface within ±5℃ or even smaller. This directly solves the core problem of uneven film performance in the prior art. This invention can stably and repeatedly prepare high-performance BDD electrodes with a diameter of not less than 150mm or a square diameter of 250mm×200mm, with a film thickness uniformity deviation of <5% and good doping uniformity.

[0023] (2) Excellent electrode performance and consistency: Thanks to the customized development and improvement of CVD equipment, the smooth inner wall design of the reaction chamber and the highly uniform deposition temperature field, the prepared large-size (such as square with a diameter ≥150mm or 250mm×200mm) BDD electrodes exhibit excellent uniformity in thickness, doping concentration, grain structure and electrochemical performance, meeting the stringent requirements of industrial applications for electrode consistency and reliability.

[0024] (3) High automation and process repeatability: The present invention adopts a fully automated control scheme integrating PLC and composite temperature measurement system, realizing one-click operation of the entire process from vacuuming, preheating, deposition to cooling. This greatly reduces human intervention, eliminates the impact of differences in operating experience, and ensures a high degree of consistency and repeatability of product performance between different batches, laying the foundation for industrial mass production.

[0025] (4) Wide applicability: The design of the liftable substrate stage enables the equipment to be flexibly compatible with a variety of substrate materials and adapt to different process requirements (such as hot wire-substrate spacing adjustment). It has a wide process window and strong adaptability. The method and device have high reliability and provide a feasible technical solution for the mass production of large-size, high-performance BDD electrodes. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the hot filament array of the device of the present invention; Figure 3 40×20 cm 2 Raman spectra of the BDD electrode, where (a) is 40 × 20 cm⁻¹. 2 Raman spectra at different positions of the BDD electrode; (b) is at 40×20 cm⁻¹ 2 Raman spectrum of the middle position of the BDD electrode; Figure 4 Large size 40×20 cm 2 The CV and LSV test results of the BDD electrode (reference silver / silver chloride electrode) are shown in the figure, where (a) is the CV plot and (b) is the LSV plot. In the diagram: 1. Reaction chamber; 2. Base; 3. Hot wire system; 3a. Central area; 3b. Transition area; 3c. Edge area; 4. Control system; 5. Thermocouple temperature monitoring unit; 6. Infrared temperature monitoring unit; 7. Gas path system; 8. Vacuum system; 9. Water cooling system; 10. Cabinet; 11. Electrode. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] like Figure 1 As shown, this embodiment provides an integrated fabrication device for large-size BDD electrodes based on multi-region synergistic thermal field control, which includes: 1) Reaction Chamber: Preferably a circular cylindrical stainless steel vacuum chamber. The inner wall of the chamber is mechanically polished to a mirror finish (e.g., Ra ≤ 0.4μm) to greatly reduce the internal surface area, prevent the adhesion of gaseous substances and the deposition of by-products, reduce the risk of contamination, and facilitate cleaning. The circular structure is beneficial for the uniform distribution of the reaction gas flow field.

[0029] 2) Substrate support platform and adjustment unit: This includes a liftable platform located within the reaction chamber for supporting the substrate. The platform is connected to the bottom of the chamber via a precision lead screw or hydraulic lifting mechanism, enabling precise vertical lifting in a vacuum environment. This allows for flexible adjustment of the distance between the hot filament array and the substrate surface to meet different process requirements.

[0030] 3) Multi-zone Independently Controllable Hot Filament System: This system is suspended above the substrate. Its core innovation lies in the fact that the hot filament system is physically and electrically divided into at least three independent temperature control zones, such as a central zone, a transition zone surrounding the central zone, and an outermost edge zone. The hot filaments in each zone are powered and controlled by an independent programmable power supply. Preferably, the hot filament density in the edge zone is greater than in the central zone, and / or the hot filaments in the edge zone are closer to the substrate surface. This differentiated design aims to pre-compensate for the temperature field attenuation caused by rapid heat dissipation in the edge zone. In terms of control strategy, a target temperature slightly higher than that of the central zone can be set for the edge zone (e.g., 5°C to 30°C higher). Through independent closed-loop control of the power of each zone, active suppression of edge effects and "coordinated" equilibrium of the temperature field are achieved.

[0031] 4) Composite temperature monitoring system: including contact temperature measurement unit and non-contact temperature measurement unit.

[0032] Contact temperature measurement unit: Inside the liftable base, at the position corresponding to the lower part of each hot wire zone, a high-precision thermocouple temperature monitoring unit (such as K-type or S-type) is embedded to directly monitor the temperature on the back of the substrate as one of the main feedback signals for temperature control.

[0033] Non-contact temperature measurement unit: A high-temperature resistant optical window is opened on the side wall of the reaction chamber, equipped with an infrared temperature monitoring unit (infrared thermometer). Its detection point is directly aimed at the corresponding area on the substrate surface to perform real-time and direct surface temperature measurement.

[0034] This composite temperature measurement system can overcome the limitations of a single temperature measurement method and obtain more accurate and comprehensive substrate temperature information.

[0035] 5) Intelligent Control System: As the brain of the device, it includes a programmable logic controller (PLC) and a host computer human-machine interface (HMI). The input of this system is connected to the composite temperature monitoring system, receiving dual signals from thermocouples and infrared thermometers; its output is connected to the independent power control unit of each hot wire zone.

[0036] The control system incorporates a weighted fusion algorithm to process contact and non-contact temperature measurement signals and calculate more accurate real-time temperature values ​​for each zone on the substrate surface.

[0037] Based on the deviation between the calculated temperature and the preset target temperature, the heating power (current / voltage) of each zone's hot wire is dynamically and independently adjusted through a closed-loop PID control algorithm, so that the temperature field of the entire substrate remains dynamically balanced.

[0038] The system has a built-in expert process database. Operators only need to select a preset process formula or set new parameters on the HMI and start the system with one click. The equipment will automatically perform all steps, including vacuuming, leak detection, preheating, introducing reaction gas, precise temperature control, deposition process control, inert gas protection cooling after deposition, and vacuum removal. This achieves full automation of the entire CVD process, greatly reducing human intervention and operational errors, and significantly improving process repeatability and stability. Each zone of the hot filament system is connected to an independent programmable power supply and current / power feedback control unit, automatically achieving "coordinated regulation" of the zone's target temperature.

[0039] 6) Auxiliary systems: Gas path system: Equipped with multiple mass flow controllers (MFCs) to precisely control the flow rates of carbon source (e.g., CH4), dopant source (e.g., B2H6, trimethylboron), hydrogen, and carrier gas. The gas inlet preferably adopts a circumferentially symmetrical design to ensure that the reactant gas flows uniformly through the deposition area.

[0040] Vacuum system: A combination of molecular and mechanical pumps is used to ensure a base vacuum of 10⁻⁶ in the reaction chamber. -4 The system operates at the Pa level, providing a clean environment for the growth of high-quality diamond films. It is equipped with an electric regulating valve and a digital vacuum gauge for automatic control and monitoring.

[0041] Water cooling system: Used to cool key components such as the base plate and assist in temperature control.

[0042] Specific device configuration: such as Figure 1 and Figure 2 As shown, the reaction chamber 1 is a circular stainless steel cavity, with a liftable base 2 installed. The hot wire system 3 uses tantalum wire and is divided into three independent temperature control zones: a central zone 3a, a transition zone 3b, and an edge zone 3c. The hot wire density in the edge zone 3c is greater than that in the central zone 3a, and the average distance between the hot wire in the edge zone 3c and the substrate surface is less than or equal to the average distance between the hot wire in the central zone 3a and the substrate surface; the spacing between the hot wires in the edge zone 3c is approximately 20% denser than that in the central zone 3a. Inside the liftable base 2, three sets of K-type thermocouple monitoring units are embedded from the center to both sides. The top of the reaction chamber 1 is equipped with a high-temperature resistant optical window, with three infrared temperature measurement windows arranged from the center to both sides, corresponding to the three hot wire zones. The gas system 7 is connected to a carbon source, a boron source, and hydrogen and protective gas respectively, and is equipped with a mass flow meter and a solenoid valve for flow control; the vacuum system 8 is connected to an external vacuum pump, and a digital display resistance vacuum meter is used for real-time measurement; the water cooling system 9 is used to regulate the temperature of the substrate on the support platform 2; the cabinet 10 is used for overall frame protection; and the electrode 11 is used to energize the hot wire for heating. The control system 4 adopts a PLC, integrating a weighted temperature fusion algorithm and a PID control program.

[0043] In this embodiment, the hot wire array has a total of five regions, and the arrangement density of the hot wires and the distance to the substrate can be adjusted independently; the electrodes 11 are also set in segments, and each segment can be adjusted up and down, so as to adjust the distance between different hot wire zones and the substrate.

[0044] Electrode preparation method The specific steps for fabricating large-size BDD electrodes using the above-described apparatus are as follows: S1: Mounting. Fix the polished and cleaned square substrate (size: 250mm × 200mm) onto the liftable base 2.

[0045] S2: One-click start. The operator selects the pre-stored preparation process formula on the HMI interface of the PLC control system 4 and clicks "Start".

[0046] S3: Automatic vacuuming and preheating. The equipment automatically starts the vacuum system to evacuate to 5×10⁸ m³ / h. -4 Pa, and a leak check is performed. Subsequently, the base 2 automatically rises to the preset height (the distance between the hot wire and the substrate is 8 mm). Hydrogen gas (500 sccm) is introduced, and the PLC control system 4 begins to perform stepped heating of the three hot wire zones 3a, 3b, and 3c according to the preset program.

[0047] S4: Multi-zone Coordinated Thermal Field Control. During the heating process, the PLC control system 4 continuously receives feedback signals from the thermocouple temperature monitoring unit and the infrared temperature monitoring unit. The system's built-in algorithm weights and fuses the two sets of signals to calculate the actual temperatures of the three regions on the substrate surface: the center, transition, and edge. Based on the preset target temperatures (center region: 780℃, transition region: 800℃, edge region: 820℃), the system dynamically adjusts the output power of each zone's power supply using a PID algorithm. For example, after reaching steady state, the actual output power of the edge region 3c will be significantly higher than that of the center region 3a to compensate for the heat radiation loss at the edge, ultimately stabilizing the temperature of all points on the entire substrate surface within the target value ±3℃. This process lasts approximately 30 minutes.

[0048] S5: Thin Film Deposition. Once the substrate temperature stabilizes, the control system automatically introduces the reaction gases: methane (CH4) at a flow rate of 30 sccm and trimethylboron (TMB) at a flow rate of 200 sccm, adjusting the working pressure to 2.5 kPa. Under the precise control of the PLC, the deposition process lasts for 8 hours. During this period, the control system monitors and adjusts the power of each zone at a frequency of 1Hz to ensure the dynamic stability of the substrate surface temperature.

[0049] S6: Cooling and Sampling. After deposition, the PLC automatically stops the supply of methane and TMB, while maintaining the operation of hydrogen (200 sccm) and the vacuum pump, and cooling is performed according to the preset cooling curve (5℃ / min). Once the substrate temperature drops below 150℃, nitrogen is introduced to atmospheric pressure, the chamber cover is raised, and the sample is removed.

[0050] Electrode performance testing: The prepared BDD electrode was characterized as follows: Appearance: The obtained film has a uniform and continuous thickness, is dense, and has no visible cracks or warping.

[0051] Raman spectroscopy (reference) Figure 3 ): Figure 3 40×20 cm 2 Raman spectroscopy analysis of the BDD electrode. At 1332 cm⁻¹ -1 The area exhibits sharp diamond characteristic peaks, sp 3 It has a high carbon content and lacks the broad peaks characteristic of non-diamond carbon (such as graphite). Wavenumber: 1332 cm⁻¹ -1 The peaks on the left and right correspond to sp 3 Carbon bonding is a characteristic signal of the diamond phase; wavenumber 1580 cm⁻¹ -1 The peaks on the left and right are sp 2 Bonded carbon belongs to the non-diamond phase. Typically, in Raman scattering, sp... 2 The sensitivity of carbon in its state is greater than that of sp 3The density of the non-diamond phase in the BDD electrode is approximately 50 times higher than that of the diamond phase, meaning that even trace amounts of non-diamond phase in the BDD electrode can be accurately detected by Raman spectroscopy. In the Raman spectrum of the BDD electrode prepared in this experiment, sp... 3 The characteristic peaks of diamond in the sp state are significantly stronger than those in the sp state. 2 The presence of non-diamond characteristic peaks in the state indicates that the purity of microcrystalline boron-doped diamond in the BDD film is extremely high. Further fitting analysis of sp 3 The carbon footprint reaches over 99.95%, fully meeting the project's SP (Special Purpose) indicators. 3 The indicator is a carbon content of ≥99%. Additionally, 1460 cm... -1 The characteristic peak at this location is a vibrational peak caused by boron doping, which verifies the effective doping of boron.

[0052] Electrochemical performance (reference) Figure 4 Electrochemical performance testing included linear sweep voltammetry (LSV) and cyclic voltammetry (CV), both performed using a CHI660E electrochemical workstation. The test system used the prepared anode as the working electrode, with a diameter of 1 × 1 cm⁻¹. 2 A platinum mesh was used as the counter electrode, and a silver / silver chloride electrode was used as the reference electrode. Both LSV and CV curves were measured in 50 mM Na₂SO₄ solution at a scan rate of 10 mV / s.

[0053] For large size 40×20 cm 2 The CV and LSV test results of the BDD electrode are as follows: Figure 4 As shown in the figure. The LSV curves show that all three large-size BDD electrodes have high potentials. The potential test used a silver / silver chloride (Ag / AgCl) electrode as a reference electrode. The potential detection result of the large-size BDD electrode was 2.899 V, which is converted to a standard hydrogen electrode (SHE) potential of 3.096 V (conversion formula: ESHE=E(Ag / AgCl)+0.197 V, 25℃).

[0054] This value is significantly higher than that of traditional ruthenium electrodes, indicating that all three BDD electrodes possess high potentials, which can effectively suppress side reactions in the electrocatalytic process. Furthermore, from 20 × 10 cm⁻¹... 2 Size enlarged to 40×20 cm 2 After specification, the LSV curves of the BDD electrodes showed a generally consistent trend, indicating that the current process can be used for scale-up production of larger-sized electrodes, ensuring the electrochemical stability of the prepared BDD electrodes. Furthermore, in the CV curve tests, when the scan rate increased from 20 mV / s to 100 mV / s, the response current showed a basically proportional increase, further verifying the excellent quality of the prepared large-sized BDD electrodes and the compliance of their electrochemical performance uniformity.

[0055] The above embodiments fully demonstrate the outstanding performance and industrial application potential of the device and method of the present invention in preparing large-size, high-performance, and highly uniform BDD electrodes.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A large-size BDD electrode integrated fabrication device based on multi-zone synergistic thermal field control, characterized in that, include Reaction chamber (1); The base (2) disposed in the reaction chamber (1) is used to support the substrate; A multi-zone independent controllable hot filament system (3) is suspended above the base (2) to provide the heat source required for deposition; the hot filament system (3) is divided into at least three electrically independent hot filament zones whose heating power can be independently controlled; An independent power control unit is electrically connected to each of the aforementioned hot filament zones; A temperature monitoring system is used to monitor in real time the temperature of the substrate surface or near surface on the base (2) and the corresponding temperature of each of the hot wire sub-regions; the temperature monitoring system includes a contact temperature measurement unit and a non-contact temperature measurement unit; The control system (4) has its signal input terminal connected to the temperature monitoring system and its control output terminal connected to each of the independent power control units. The control system (4) is configured to: receive the temperature signal from the temperature monitoring system, calculate the characterization temperature of each partition on the substrate surface through an algorithm, and dynamically and independently adjust the heating power of each hot wire partition by comparing the characterization temperature with the preset target temperature of each partition, so as to achieve coordinated control of the thermal field on the substrate surface and make the temperature field on the substrate surface tend to be uniform.

2. The integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control according to claim 1, characterized in that, The hot wire partition includes a central region (3a), a transition region (3b) surrounding the central region (3a), and an edge region (3c) surrounding the transition region (3b).

3. The integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control according to claim 2, characterized in that, The filament arrangement density in the edge region (3c) is greater than that in the central region (3a), and the average distance between the filament in the edge region (3c) and the substrate surface is less than or equal to the average distance between the filament in the central region (3a) and the substrate surface.

4. The integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control according to claim 1, characterized in that, The contact temperature measurement unit is a plurality of thermocouple temperature monitoring units (5) embedded inside the base (2) and corresponding to the positions of each hot wire partition; the non-contact temperature measurement unit is one or more infrared temperature detection units (6) that are aligned with each partition of the substrate surface through a window set on the wall of the reaction chamber (1).

5. The integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control according to claim 1, characterized in that, The base (2) is designed to be height-adjustable and is connected to the bottom of the reaction chamber (1) via a lifting mechanism to adjust the distance between the hot wire system (3) and the substrate surface.

6. The integrated fabrication device for large-size BDD electrodes based on multi-zone synergistic thermal field control according to claim 1, characterized in that, The device also includes an external cabinet (10) and a gas system (7), a vacuum system (8) and a water cooling system (9) connected to the interior of the reaction chamber (1).

7. A method for fabricating large-size boron-doped diamond electrodes using the apparatus described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Place the large-size substrate on the base (2); S2: Start the hot wire system (3), and execute multi-zone coordinated thermal field regulation through the control system (4) to heat the substrate surface to the deposition temperature and stabilize it at the preset target temperature value, wherein the target temperature value set for the edge area of ​​the substrate surface is higher than the target temperature value set for the center area of ​​the substrate surface. S3: A reaction gas containing carbon source, hydrogen and boron dopant source is introduced into the reaction chamber (1) through the gas path system (7), and a boron doped diamond film is deposited on the substrate under the control of the multi-zone synergistic thermal field. S4: After deposition, stop the flow of reaction gas and cool under controlled conditions to obtain the large-size boron-doped diamond electrode.

8. The method for preparing large-size boron-doped diamond electrodes according to claim 7, characterized in that, In step S2, the difference between the target temperature value of the edge region and the target temperature value of the center region of the substrate surface is 5°C to 30°C.

9. The method for preparing large-size boron-doped diamond electrodes according to claim 7, characterized in that, The control system (4) continuously adjusts the heating power of each hot wire zone according to the feedback from the temperature monitoring system, so that the temperature fluctuation range of each area on the substrate surface is controlled within ±5℃.

10. A large-size boron-doped diamond electrode, characterized in that, It is prepared by the method of any one of claims 7-9, wherein the oxygen evolution potential difference in different regions of the electrode surface is less than 0.1V and the electrochemical active area deviation is less than 5%.

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