Regulation and control method for ion beam sputtering

Abstract

The invention provides a regulation and control method for ion beam sputtering. The regulation and control method comprises the following steps that bias voltage is configured at a target end; the current film forming stress bias pressure is configured to compensate the beam pressure of the ion source; according to the use state of the ion source grid mesh and the target film forming rate, normal operation values of the current film forming stress beam pressure and the current film forming stress bias pressure are configured; obtaining a current film forming rate and a current film forming stress; if the current film forming rate is lower than the first rate threshold value or higher than the second rate threshold value, and / or if the current film forming stress is lower than the first stress threshold value or higher than the second stress threshold value, a beam pressure adjusting value and / or a bias pressure adjusting value are / is obtained through a minimum objective function. In addition, the service life of the grid mesh, the film forming efficiency and the film forming stress are balanced through the minimum objective function, the film forming efficiency and the film forming quality can be controlled while the service life of the grid mesh is considered, and the use performance and applicability of the method are improved.

Description

Technical Field

[0001] This application relates to the field of ion beam sputtering technology, and more specifically, to a method for controlling ion beam sputtering. Background Technology

[0002] Ion beam sputtering (IBS) is a physical vapor deposition technique that uses a collimated ion beam to bombard a target material in a high-vacuum environment to achieve thin film deposition. Its advantage lies in the ability to precisely control the film thickness and microstructure by adjusting the ion beam energy (20~50 keV) and beam current density (0~180 mA).

[0003] In existing technologies, ion beam sputtering accelerates the formation of a high-energy beam using a grid, such as a common three-layer grid structure consisting of a deceleration grid, a shielding grid, and an accelerating grid. To ensure the deposition rate of ion beam sputtering, the grid often needs to operate under high loads, such as high voltage and high current density. However, high load operation accelerates grid corrosion and wear, shortening its lifespan. Furthermore, for targets with high melting points, high stability, and high dielectric constants, the ion source for ion beam sputtering needs to provide ion beams with even greater energy. This further exacerbates the grid load, causing conventional ion beam sputtering systems to experience a decrease in deposition rate when sputtering targets with high melting points, high stability, and high dielectric constants, or requiring more frequent grid replacements. Consequently, this limits the application of ion beam sputtering or increases maintenance costs. Summary of the Invention

[0004] This application addresses the shortcomings of existing methods by proposing a control method for ion beam sputtering, which solves at least one of the technical problems of shortened grid lifetime, low deposition efficiency of difficult-to-sputter targets, or uncontrollable deposition process in related technologies.

[0005] This application provides a method for controlling ion beam sputtering, comprising the following steps: Configure a bias voltage at the target end; The bias voltage is configured to compensate for the beam voltage of the ion source; Configure the normal operating values ​​of the beam voltage and the bias voltage according to the usage status of the ion source grid and the target film formation rate; Obtain the current film formation rate and current film formation stress; If the current film formation rate is lower than a first rate threshold or higher than a second rate threshold, and / or if the current film formation stress is lower than a first stress threshold or higher than a second stress threshold, the beam pressure adjustment value and / or the bias pressure adjustment value are obtained through the minimum objective function.

[0006] Specifically, the main technical concept of this application lies in setting the normal operating value for ion beam sputtering based on the grid's usage status and target film deposition rate under the coordination of the bias voltage. This effectively reduces the grid load and extends grid lifetime. Simultaneously, this application balances grid lifetime with film deposition efficiency and stress through a minimum objective function. While ensuring grid lifetime, it fully leverages the controllable effects of bias voltage and beam voltage, controlling film deposition efficiency and stress while considering grid lifetime, thus improving the application's performance and applicability.

[0007] Furthermore, the ion source is configured as a radio frequency ion source.

[0008] Specifically, another technical concept of this application is to further reduce the load on the grid by using a radio frequency ionization system, which is mainly achieved by reducing the grid beam voltage, thereby further improving the grid's service life.

[0009] Furthermore, configuring the normal operating values ​​of the beam voltage and the bias voltage includes: The usage state is defined as any one of the first state, second state, and third state based on ion transmittance or grid structure damage. When the usage state is defined as the first state, the standard beam pressure and standard bias pressure corresponding to the target film formation rate are used as the normal operating values. When the usage state is defined as the second state, the standard beam pressure is corrected by a scaling factor to obtain a corrected beam pressure, and the corrected bias pressure is derived in reverse based on the target film formation rate and the corrected beam pressure, and the corrected beam pressure and the corrected bias pressure are used as the normal operating values. When the usage state is defined as the third state, a warning or shutdown will be issued.

[0010] Specifically, another technical concept of this application is to determine the normal operating value and perform operation warning through the first state, the second state and the third state, so that the most suitable operating beam voltage and operating bias voltage can be adapted based on the grid state, so as to give full play to the use value of the grid while ensuring film formation performance. This can effectively improve the service life of the grid and ensure the film formation performance of ion beam sputtering.

[0011] Furthermore, the beam pressure adjustment value is obtained through a minimum objective function, and / or the bias pressure adjustment value includes: Minimize the objective function by constraining the target energy consumption; The square of the difference between the current film formation rate and the target film formation rate is used as the first factor and assigned a first weight; The square of the difference between the current film-forming stress and the target film-forming stress is used as a second factor and assigned a second weight; The sum of the square of the beam pressure adjustment value and the square of the bias pressure adjustment value is used as a third factor and assigned a third weight; The beam pressure adjustment value and the bias pressure adjustment value are solved by the minimum objective function.

[0012] Specifically, another technical concept of this application is to solve for the beam voltage adjustment value and bias voltage adjustment value using the target energy consumption, thereby balancing energy consumption and grid lifespan to obtain the minimum energy consumption and reduce sputtering costs. The solution for the beam voltage adjustment value and bias voltage adjustment value is also related to the current film deposition rate, current film deposition stress, target film deposition rate, and target film deposition stress. Therefore, based on the target film deposition rate and target film deposition stress, the beam voltage adjustment value and bias voltage adjustment value are dynamically adjusted to obtain the minimum beam voltage adjustment value and bias voltage adjustment value for the grid while satisfying the target film deposition rate and target film deposition stress, thus balancing film deposition efficiency, film deposition quality, and grid lifespan.

[0013] Furthermore, when the usage state is defined as the first state and the target material at the target end is a high-dielectric material or a high-bonding-strength material, the value of the first weight is increased; Alternatively, when the usage state is defined as the first state and the target film density is greater than the film density threshold, the value of the second weight is increased; Alternatively, when the usage state is defined as the second state, the value of the third weight is increased.

[0014] Specifically, another technical concept of this application is that the proportions of the first weight, the second weight, and the third weight can be adjusted based on the material of the target and the usage status of the grid, thereby achieving a balance between film formation rate, film formation quality, and grid lifetime.

[0015] Optionally, when the current film formation rate is less than the first rate threshold or when the current film formation stress is less than the first stress threshold, the obtained bias pressure adjustment value is used to increase the bias pressure.

[0016] Optionally, when the current film-forming stress is greater than the second stress threshold, the obtained bias pressure adjustment value is used to reduce the bias pressure.

[0017] Optionally, when the current film formation rate is greater than the second rate threshold, the obtained beam pressure adjustment value is used to increase the beam pressure.

[0018] Optionally, obtain the current beam; When the current beam current is less than the minimum allowable beam current, the beam pressure adjustment value obtained by solving is used to reduce the beam pressure and update the normal operating value.

[0019] Specifically, another technical concept of this application is to restore the normal operation of ion beam sputtering and improve the reliability of this application by re-establishing normal operating values ​​in extreme situations such as when the film formation rate or film formation stress is difficult to meet the requirements, or when the film formation rate or film formation stress exceeds expectations or when the beam current is difficult to maintain for ion beam sputtering.

[0020] In some possible embodiments, a bias voltage circuit is configured at the target end for adjusting the bias voltage; Configure an ion source to adjust the beam pressure; Configure a detection module to acquire the usage status, current film formation rate, and current film formation stress; A control module is configured and connected to the bias voltage circuit, ion source and detection module respectively, for obtaining the beam voltage adjustment value and / or the bias voltage adjustment value through the minimum objective function.

[0021] The beneficial technical effects of the technical solutions provided in this application include: This application compensates for the beam voltage by configuring the target bias voltage, allowing the beam voltage to be reduced within a certain range. This reduction in beam voltage reduces the grid load and, consequently, extends the grid lifetime. Simultaneously, the control of beam voltage and bias voltage is constrained by the grid state, film deposition rate, and film stress and their combination, thus balancing the stability of film deposition performance with the improvement of grid lifetime.

[0022] Meanwhile, this application also utilizes a minimum objective function to obtain the beam voltage and bias voltage for adjustment, and balances the film deposition rate, film stress, and grid lifetime by setting weight values. While satisfying film deposition performance, the beam voltage is minimized to the maximum extent, thereby extending the grid lifetime. Furthermore, the balance between film deposition rate and film stress facilitates applicability to different target materials and substrates with different film deposition requirements, expanding the application scenarios of this application.

[0023] In addition, the minimum objective function is also used for real-time correction of film formation rate and film stress. By dynamically adjusting the weight values, the film formation rate and film stress are corrected, thereby improving the stability of the film formation process.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0025] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 A schematic flowchart illustrating a method for controlling ion beam sputtering according to an embodiment of this application; Figure 2 This is a schematic diagram of the composition of an ion beam sputtering control device provided in an embodiment of this application. Detailed Implementation The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0026] Those skilled in the art will understand that, unless specifically stated otherwise, the terms "described" and "the" as used herein may also include plural forms. It should be further understood that the term "comprising" as used in the specification of this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by this art. The term "and / or" as used herein refers to at least one of the items defined by the term; for example, "A and / or B" can be implemented as "A," or as "B," or as "A and B."

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0028] This application mainly relates to a method for controlling ion beam sputtering. It primarily compensates for the beam voltage by configuring the target bias voltage, allowing the beam voltage to be reduced within a certain range. This reduction in beam voltage leads to a decrease in grid load, thereby extending grid lifetime. Simultaneously, the control of beam voltage and bias voltage is constrained by grid state, film deposition rate, and film stress and their interactions, aiming to balance stable film deposition performance with improved grid lifetime.

[0029] The research and development approach of this application includes: improving lifespan by reducing grid load. However, the reduction in grid load, primarily beam voltage, inevitably leads to a decrease in ion beam sputtering efficiency. To compensate for this reduction, this application incorporates a bias voltage at the target end. Furthermore, based on the introduction of the bias voltage, this application uses a minimum objective function to obtain the beam voltage adjustment value and the bias voltage adjustment value, thereby balancing grid lifetime, film deposition rate, and film deposition quality. This approach extends grid lifetime while simultaneously controlling the film deposition rate and quality, thus improving the performance and applicability of this application.

[0030] The technical solution of this application and how it solves the above-mentioned technical problems are described in detail below with specific embodiments. It should be noted that the following embodiments can be referenced, borrowed, or combined with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be described again.

[0031] For a detailed explanation of the ion beam sputtering control method provided in this application, please refer to [reference needed]. Figure 2 This is a schematic diagram of the composition of an ion beam sputtering control device provided in an embodiment of this application.

[0032] Specifically, ion beam sputtering is a physical vapor deposition technique that achieves thin film deposition by bombarding a target material with a collimated ion beam under high vacuum. This process utilizes a monoenergetic ion beam generated by ion source 3 to bombard the target surface, causing target atoms to be sputtered onto the surface of substrate 1 with high kinetic energy, forming a dense thin film. Therefore, in Figure 2 In this design, substrate 1 and target 2 are placed in a vacuum environment provided by a vacuum chamber (not shown in the figure). An ion beam generated by ion source 3 bombards the target material (not shown in the figure) on target 2, causing target atoms to be sputtered onto substrate 1 to form a dense thin film. The grid (not shown in the figure) is one of the core structures of the grid-type ion source 3, consisting of many parallel metal lines spaced equally apart to form numerous channels. The range of ion kinetic energy that can pass through can be selected by adjusting the potential and shape of the grid. The grid is typically a three-layer structure, including a screen grid, an accelerating grid, and a ground grid. Since the main technical concept of this application is to extend the service life of the grid, its structural composition and installation positioning are not subject to excessive restrictions. Because the grid needs to operate under high voltage and high current density in the ion source 3, its structural corrosion and sputtering loss are mainly affected by the beam pressure and beam current. If it is under continuous high operating beam pressure, its service life will be shortened, the replacement frequency will increase, and the operating cost will increase. Therefore, this application provides a bias voltage circuit 4 at the target end 2. The bias voltage circuit 4 is used to supplement the beam voltage of the ion source 3, thereby reducing the beam voltage of the ion source 3 and extending the grid lifetime. Simultaneously, the ion beam sputtering control device provided in this application also includes a detection module for acquiring the usage status, current film formation rate, and current film formation stress, as well as a control module connected to the bias voltage circuit 4, the ion source 3, and the detection module respectively.

[0033] Further, please refer to Figure 1 This is a schematic flowchart of a method for controlling ion beam sputtering according to an embodiment of this application.

[0034] Specifically, in combination Figure 2The working principle of this application is as follows: A bias voltage circuit 4 is configured at the target end 2 to provide a bias voltage, which is used to supplement the beam voltage of the ion source 3, thereby enabling the grid to operate normally under a lower beam voltage and reducing its workload. Simultaneously, the control module configures the normal operating values ​​of the beam voltage and bias voltage according to the grid's usage status and the target film deposition rate, where the target film deposition rate refers to the film deposition rate preset as needed during operation. Then, during ion beam sputtering, the current film deposition rate and current film deposition stress on the substrate 1 are acquired in real time by the detection module. If the current film deposition rate and current film deposition stress meet the requirements, no adjustment of the beam voltage and bias voltage is needed to achieve film deposition on the substrate 1; if either the current film deposition rate or the current film deposition stress does not meet the requirements, the bias voltage and beam voltage need to be adjusted to avoid affecting the film deposition efficiency and quality of the substrate 1. Specifically, if the current film deposition rate is lower than a first rate threshold or higher than a second rate threshold, and / or if the current film deposition stress is lower than a first stress threshold or higher than a second stress threshold, the beam voltage adjustment value and / or the bias voltage adjustment value are obtained through a minimum objective function. Since the normal operating values ​​are confirmed based on the grid's usage status and the target film deposition rate, the grid's workload can be reduced, extending its service life. Furthermore, during the film deposition process on substrate 1, the beam voltage adjustment value and bias voltage adjustment value are obtained through a minimum objective function to dynamically adjust the normal operating values. This ensures that the current film deposition rate and current film deposition stress always meet the requirements of the target film deposition rate and target film deposition stress, thereby improving film deposition efficiency and quality.

[0035] Optionally, the ion source 3 of this application is configured as a radio frequency ion source 3. Since the radio frequency ion source 3 does not rely on electron bombardment of the grid for ignition, but maintains high-density plasma through a radio frequency electric field, its ion energy has a wider adjustable range. This allows the ion source 3 to still generate a high-energy, highly directional ion beam under low voltage conditions, thereby reducing the grid burden and extending its service life.

[0036] Optionally, the current density of the radio frequency ion source 3 is 0.5~5 mA / cm2. It is worth explaining that the radio frequency ion source 3 can reduce the beam current by 20%~40% compared to the conventional ion source 3, thereby extending the grid lifespan by 50%.

[0037] Optionally, this application defines the usage state as any one of the first, second, and third states based on ion transmittance or grid damage. Ion transmittance refers to the proportion of ions generated from the ion source 3 that pass through the grid and ultimately reach the target end 2. It is a key performance indicator affecting ion bombardment sputtering efficiency, i.e., film formation rate, and can be obtained through current beam current detection or through existing formulas for calculating ion transmittance. Grid damage is determined by characteristics such as mesh corrosion, aperture change, and grid thermal deformation.

[0038] Furthermore, by defining the first state as normal grid, the second state as grid aging, and the third state as grid failure, the usage state can be determined by setting ion transmittance thresholds. For example, defining the first transmittance threshold as 90% to determine the first and second states, and defining the second transmittance threshold as 70% to determine the second and third states, that is, when the ion transmittance is greater than the first transmittance threshold of 90%, the usage state is defined as the first state, i.e., normal grid; the ion transmittance is less than the first transmittance threshold of 70% but greater than the second transmittance threshold of 70%, which is the second state, i.e., grid aging; and the ion transmittance is less than the second transmittance threshold of 70%, which is the third state, i.e., grid failure. 90% and 70% are only used as explanations of the first and second transmittance thresholds and are not used for actual limitation. Specific values, such as 95%, 85%, 75%, 60%, etc., are selected based on the actual needs of ion beam sputtering and the expected grid lifetime. Similarly, defining the usage state based on grid structural damage is similar to defining it based on ion transmittance. The difference lies in the choice of damage threshold for the grid structure, which differs from the ion transmittance. For example, using pore size change as the criterion, a 10% increase in pore size can be defined as the threshold for the first and second states, and a 25% increase as the threshold for the second and third states. Alternatively, using mesh corrosion as the criterion, a 5% corrosion rate can be defined as the threshold for the first and second states, and a 15% corrosion rate as the threshold for the second and third states. It is important to clarify that the values ​​of 10% pore size increase, 25% pore size increase, 5% corrosion rate, and 15% corrosion rate are merely examples and can be selected based on actual needs.

[0039] It is worth explaining that by defining the first, second, and third states and using the minimum objective function, the lifespan of the grid can be extended by 20% to 50%.

[0040] Furthermore, after defining the first, second, and third states, this application allows for the use of the standard beam pressure and standard bias pressure corresponding to the target film deposition rate as the normal operating values ​​when the first state is defined. The target film deposition rate is an expected set value for the film deposition rate, which can be set through the equipment's own parameters. Based on the equipment's performance, the target film deposition rate determines the standard beam pressure and standard bias pressure. These normal operating values ​​define the normal operating values ​​during ion beam sputtering. When the current film deposition rate and current film deposition stress meet expectations, ion beam sputtering can continue using these normal operating values. In other words, when the grid is normal, this application performs ion beam sputtering according to the standard beam pressure and standard bias pressure to fully utilize the grid's performance and ensure that the ion beam sputtering operates at standard performance.

[0041] When the operating state is defined as the second state, the standard beam pressure is corrected using a scaling factor to obtain a corrected beam pressure. The corrected bias pressure is then derived in reverse based on the target film deposition rate and the corrected beam pressure, with both the corrected beam pressure and the corrected bias pressure serving as the normal operating values. For example, the second state refers to grid aging, with a scaling factor of 0.5~0.9. This reduces the load on the grid by lowering the standard beam pressure, thereby extending the grid's performance. Since the standard beam pressure decreases in the second state, the standard bias pressure increases synchronously to ensure sputtering performance, primarily derived in reverse from the target film deposition beam current and the corrected beam pressure. Because the definition of the second state allows for a reduction in the standard beam pressure when grid aging occurs, the load on the grid is reduced, thus extending its service life.

[0042] Optionally, this application can further refine the second state to fully utilize the performance of the grid when it is at different aging levels. For example, still taking a proportionality coefficient of 0.5~0.9 as an example, the proportionality coefficient can be divided into a first coefficient of 0.5~0.7 and a second coefficient of 0.7~0.9, thereby subdividing the second state into second state a—mild aging and second state b—severe aging. Further subdivision based on ion permeability or grid structure damage defines the usage state as mild aging or severe aging. Thus, a second coefficient of 0.7~0.9 is configured for mild aging, and a first coefficient of 0.5~0.7 is configured for severe aging, fully utilizing its performance while ensuring the grid's service life.

[0043] When the usage status is defined as the third state, that is, the aging degree of the grid has caused it to lose its normal function, i.e. the grid is scrapped, an early warning or shutdown is issued to prompt the replacement of the grid and ensure the normal operation of ion beam sputtering.

[0044] It is worth explaining that the values ​​of the standard beam pressure and the proportional coefficient are constrained by the operating parameters of the radio frequency ion source 3, while the value of the standard bias voltage is constrained by the ion beam angle.

[0045] Optionally, the minimum value of the corrected bias voltage is greater than the bias voltage value corresponding to a beam angle of 15° for the ion beam under the maximum corrected beam voltage.

[0046] Optionally, the maximum value of the corrected bias voltage is less than the bias voltage value corresponding to a beam angle of 25° for the ion beam under the maximum corrected beam voltage.

[0047] It is worth explaining that the ion beam angle determines the bombardment range of the target. If the beam angle is too small, the target utilization rate decreases. While increasing the beam angle can improve the target utilization rate, the excessive dispersion of the ion beam leads to a decrease in bombardment kinetic energy density, which in turn reduces sputtering efficiency. Therefore, this application, through the aforementioned limitations of the bias voltage and the modified beam voltage, can significantly improve the target utilization rate without affecting the bombardment sputtering efficiency. In essence, the ion source 3 has already formed a corresponding ion beam angle under the standard or modified beam voltage. The role of the bias voltage is to change the sheath structure in front of the target through the bias electric field it generates, causing the ion beam to accelerate secondaryly when it approaches the target, thereby increasing its bombardment kinetic energy and bombardment beam angle.

[0048] Optionally, the bias voltage ranges from 50V to 500V. Based on the secondary acceleration effect of the bias voltage, the bombardment range of the ion beam can be effectively improved, thereby increasing the utilization rate of the target material by 15% to 30%.

[0049] Furthermore, this application primarily obtains the beam pressure adjustment value and / or bias pressure adjustment value through a minimum objective function, thereby dynamically adjusting the standard beam pressure and / or standard bias pressure in the normal operating values. It can be understood that when the operating state is defined as the first state, the beam pressure adjustment value and / or bias pressure adjustment value adjusts the standard beam pressure and / or standard bias pressure, while when the operating state is defined as the second state, the beam pressure adjustment value and / or bias pressure adjustment value adjusts the modified beam pressure and / or modified bias pressure. That is, the minimum objective function acts on the corresponding normal operating values ​​based on the operating state.

[0050] Furthermore, this application uses the target energy consumption to constrain the minimum objective function. The objective function is a core concept in machine learning and optimization problems, used to measure the difference between the model's predicted value and the actual value. By minimizing the objective function, the optimal parameters of the prediction model can be found, thereby improving the ion beam sputtering performance. Therefore, this application mainly uses the target energy consumption to constrain the minimum objective function. Since the current film formation rate, target film formation rate, current film formation stress, and target film formation stress are known values, this application uses the sum of the squares of the beam pressure adjustment value and the squares of the bias pressure adjustment value as a third factor. Therefore, the optimal beam pressure adjustment value and / or bias pressure adjustment value can be obtained under the minimum energy consumption of the ion beam through the minimum objective function. That is, this application can reduce the energy consumption in the ion beam sputtering process during the dynamic adjustment of the beam pressure adjustment value and / or bias pressure adjustment value. Meanwhile, the current film-forming rate and the target film-forming rate, as well as the current film-forming stress and the target film-forming stress, serve as the first and second factors of the minimum objective function. Solving the minimum objective function can also make the current film-forming rate converge to the target film-forming rate and the current film-forming stress converge to the target film-forming stress, thereby achieving control over film-forming efficiency and film-forming quality.

[0051] Optionally, the model of the minimum objective function in this application is: );in, This refers to the target energy consumption. This refers to the first weight. This refers to the second weight. This refers to the third weight. This refers to the current film formation rate. This refers to the target film formation rate. This refers to the current film-forming stress. This refers to the target film-forming stress. This refers to the beam pressure adjustment value. This refers to the bias voltage adjustment value.

[0052] Optionally, , This refers to the standard or corrected beam pressure under normal operating conditions. It refers to the process of Adjusted beam pressure; , This refers to the standard bias voltage or corrected bias voltage under normal operating conditions. It refers to the process of Adjusted bias voltage.

[0053] Optionally, the current film deposition rate is obtained through a film thickness monitoring component, such as quartz crystal monitoring or optical monitoring. The current film deposition rate is obtained by detecting the change in film thickness over time on substrate 1. That is, the current film deposition rate is used to characterize the ion beam sputtering deposition rate. In other words, the ion beam sputtering deposition rate can be controlled by minimizing the objective function.

[0054] Optionally, if the current film deposition rate is less than the first rate threshold, the obtained bias voltage adjustment value is used to increase the bias voltage to update the normal operating value. The first rate threshold refers to the limit value at which the target deposition rate does not meet the usage requirements. That is, if the current film deposition rate does not meet the film deposition requirements, the acceleration performance of the ion beam is increased by increasing the bias voltage, i.e., the obtained bias voltage adjustment value is used to increase the bias voltage. This increases the bombardment kinetic energy and bombardment angle of the ion beam, thereby increasing the film deposition rate so that the current film deposition rate is greater than the first rate threshold.

[0055] Optionally, if the current film deposition rate exceeds the second rate threshold, the obtained beam pressure adjustment value is used to increase the beam pressure and update the normal operating value. The second rate threshold refers to the limit value at which an excessively high target deposition rate causes a decrease in film quality. That is, if the current film deposition rate is too high, the energy of the ion beam is stabilized by increasing the beam pressure, thereby stabilizing the film quality. It is worth understanding that if the current film deposition rate exceeds the first rate threshold, the obtained bias pressure adjustment value can also be used to decrease the bias pressure. By reducing the ion beam bombardment kinetic energy, the film quality is stabilized. Compared to increasing the beam pressure, decreasing the bias pressure, by reducing the film deposition rate, is a more reliable way to stabilize the film quality.

[0056] Optionally, the second rate threshold is greater than the first rate threshold.

[0057] Optionally, the current film formation stress can be determined by detecting the ion beam energy distribution and beam angle distribution. That is, the current film formation stress is used to characterize the film stress, and the film stress of ion beam sputtering deposition can be controlled by minimizing the objective function.

[0058] Optionally, if the current film-forming stress is less than the first stress threshold, the obtained bias voltage adjustment value is used to increase the bias voltage to update the normal operating value. The first stress threshold refers to the limit value at which the film layer stress of substrate 1 does not meet the usage requirements. That is, if the current film-forming stress does not meet the film-forming requirements, the acceleration performance of the ion beam is increased by increasing the bias voltage, i.e., the obtained bias voltage adjustment value is used to increase the bias voltage. This increases the bombardment kinetic energy and bombardment angle of the ion beam, thereby increasing the number of target atoms and achieving film densification, so that the current film-forming stress is greater than the first stress threshold.

[0059] Optionally, if the current film-forming stress exceeds the second stress threshold, the obtained bias voltage adjustment value is used to reduce the bias voltage and update the normal operating value. The second stress threshold refers to the limit value of stress for preparing a porous layer on substrate 1. That is, if the current film-forming stress cannot meet the requirements for preparing a porous layer, the energy bombardment of the ion beam is reduced by lowering the bias voltage, thereby reducing the porousness of the film. It is worth explaining that a porous layer refers to the requirement of a specific low-stress film layer. Since some devices need to be used as buffer layers, etc., a low-stress film layer needs to be obtained. Therefore, a porous layer structure can be obtained by lowering the bias voltage. Thus, when the current film-forming stress exceeds the second stress threshold, the bias voltage adjustment value obtained by solving the problem can be used to reduce the bias voltage, instead of using the obtained beam voltage adjustment value to reduce the beam voltage, to avoid the beam current becoming too small due to the reduced beam voltage, which would lead to unstable ion beam output.

[0060] Optionally, the first stress threshold is greater than the second stress threshold.

[0061] Optionally, this application also obtains the current beam current; when the current beam current is less than the minimum allowable beam current, the obtained bias voltage adjustment value is used to increase the bias voltage to update the normal operating value. It is understood that the minimum allowable beam current refers to the minimum beam current required to maintain the ion beam. That is, this application stabilizes the beam current by increasing the bias voltage, thereby preventing the ion source 3 from extinguishing due to excessively low beam current, thus improving the reliability of this application. Of course, the beam current can also be stabilized by increasing the beam voltage, but a simultaneous increase in beam voltage and beam current would lead to a multiple increase in the grid load, which would be counterproductive. That is, when the beam current is less than the minimum allowable beam current, while the obtained bias voltage adjustment value is used to increase the bias voltage, the obtained beam current adjustment value is also used to decrease the beam current to balance the grid load.

[0062] Optionally, when the usage state is defined as the first state and the target material of the target end 2 is a high dielectric material or a high bonding material, the value of the first weight is increased. It is worth explaining that the sum of the first, second, and third weights is 1. Therefore, based on the structure of the minimum objective function, increasing the weights means increasing the influence of the corresponding factors on the target energy consumption. That is, given a fixed target energy consumption, if the weight of one factor increases, it will inevitably lead to a decrease in the weights of other factors. In other words, when the first weight is increased, the influence of the third weight will be compressed, resulting in the beam voltage not being reduced to the maximum extent, and increasing the load on the grid. That is, increasing the first weight is used to improve the film formation rate. By sacrificing the grid lifetime, this application increases the sputtering rate of high-dielectric or high-bonding-density materials. Since the atomic bonding of high-dielectric or high-bonding-density materials is more compact, the required bombardment energy is also greater. It is estimated that the ion beam needs a larger energy output. At this time, simply increasing the bias voltage is not enough to meet the sputtering efficiency requirements. It is also necessary to increase the beam current, so that this application can sputter high-dielectric or high-bonding-density materials, improving the applicability of this application. For example, materials such as Ta2O5 and HfO2. This application can increase the deposition rate of high dielectric constant or high bonding density materials by 30%–50% by increasing the first weight and dynamically adjusting the bias voltage value.

[0063] Similarly, when a high-density film layer is required, the second weighting method can be used to increase the film layer stress, thereby improving the applicability of this application to the requirement of a high-density film layer.

[0064] Conversely, in scenarios involving conventional target sputtering or conventional film density fabrication, the grid load can be reduced by adding a third weight, thereby extending the grid's lifespan.

[0065] It is worth understanding that the adjustment of the first, second, and third weights is used for different application scenarios to meet the different needs of high dielectric constant targets, high bonding targets, high-density films, loose films, and extended grid lifetime.

[0066] Alternatively, the minimum objective function can also be configured with a fourth factor and a fourth weight based on other requirements of the membrane layer. The role of the fourth factor and the fourth weight can be understood by referring to the role of the first factor and the first weight, as well as the role of the second factor and the second weight.

[0067] Optionally, in sputtering of high dielectric constant targets and insulating targets, this application also provides a neutralizing electron source (not shown in the figure) to avoid target poisoning.

[0068] In summary, this application provides a method for controlling ion beam sputtering. A bias voltage circuit 4 is configured at the target end 2 to provide a bias voltage, which is used to supplement the beam voltage of the ion source 3, thereby enabling the grid to operate normally under a lower beam voltage and reducing its workload. Simultaneously, a control module configures the normal operating values ​​of the beam voltage and bias voltage according to the grid's usage status and the target film deposition rate, where the target film deposition rate refers to the film deposition rate preset as needed during operation. Then, during ion beam sputtering, the current film deposition rate and current film deposition stress on the substrate 1 are acquired in real time by a detection module. If the current film deposition rate and current film deposition stress meet the requirements, no adjustment of the beam voltage and bias voltage is needed to achieve film deposition on the substrate 1; if either the current film deposition rate or the current film deposition stress does not meet the requirements, the bias voltage and beam voltage need to be adjusted to avoid affecting the film deposition efficiency and quality of the substrate 1. Specifically, if the current film deposition rate is lower than a first rate threshold or higher than a second rate threshold, and / or if the current film deposition stress is lower than a first stress threshold or higher than a second stress threshold, the beam voltage adjustment value and / or the bias voltage adjustment value are obtained through a minimum objective function. Since the normal operating values ​​are confirmed based on the grid's usage status and the target film deposition rate, the grid's workload can be reduced, extending its service life. Furthermore, during the film deposition process on substrate 1, the beam voltage adjustment value and bias voltage adjustment value are obtained through a minimum objective function to dynamically adjust the normal operating values. This ensures that the current film deposition rate and current film deposition stress always meet the requirements of the target film deposition rate and target film deposition stress, thereby improving film deposition efficiency and quality.

[0069] Those skilled in the art will understand that the steps, measures, and solutions in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and solutions in related technologies that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0070] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate directions or positional relationships based on the exemplary directions or positional relationships shown in the accompanying drawings. They are used to facilitate the description or simplification of the embodiments of this application and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0071] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0073] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0074] The above description is only a partial implementation of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application, without departing from the technical concept of this application, also fall within the protection scope of the embodiments of this application.

Claims

1. A method for controlling ion beam sputtering, characterized in that, Includes the following steps: Configure a bias voltage at the target end; The bias voltage is configured to compensate for the beam voltage of the ion source; Configure the normal operating values ​​of the beam voltage and the bias voltage according to the usage status of the ion source grid and the target film formation rate; Obtain the current film formation rate and current film formation stress; If the current film formation rate is lower than a first rate threshold or higher than a second rate threshold, and / or if the current film formation stress is lower than a first stress threshold or higher than a second stress threshold, the beam pressure adjustment value and / or the bias pressure adjustment value are obtained through the minimum objective function.

2. The method for controlling ion beam sputtering as described in claim 1, characterized in that, The ion source is configured as a radio frequency ion source.

3. The method for controlling ion beam sputtering as described in claim 1 or 2, characterized in that, The normal operating values ​​for configuring the beam voltage and the bias voltage include: The usage state is defined as any one of the first state, second state, and third state based on ion transmittance or grid structure damage. When the usage state is defined as the first state, the standard beam pressure and standard bias pressure corresponding to the target film formation rate are used as the normal operating values. When the usage state is defined as the second state, the standard beam pressure is corrected by a scaling factor to obtain a corrected beam pressure, and the corrected bias pressure is derived in reverse based on the target film formation rate and the corrected beam pressure, and the corrected beam pressure and the corrected bias pressure are used as the normal operating values. When the usage state is defined as the third state, a warning or shutdown will be issued.

4. The method for controlling ion beam sputtering as described in claim 3, characterized in that, The beam pressure adjustment value is obtained by minimizing the objective function, and / or the bias pressure adjustment value includes: Minimize the objective function by constraining the target energy consumption; The square of the difference between the current film formation rate and the target film formation rate is used as the first factor and assigned a first weight; The square of the difference between the current film-forming stress and the target film-forming stress is used as a second factor and assigned a second weight; The sum of the square of the beam pressure adjustment value and the square of the bias pressure adjustment value is used as a third factor and assigned a third weight; The beam pressure adjustment value and the bias pressure adjustment value are solved by the minimum objective function.

5. The method for controlling ion beam sputtering as described in claim 4, characterized in that, When the usage state is defined as the first state and the target material at the target end is a high dielectric material or a high bonding material, the value of the first weight is increased; Alternatively, when the usage state is defined as the first state and the target film density is greater than the film density threshold, the value of the second weight is increased; Alternatively, when the usage state is defined as the second state, the value of the third weight is increased.

6. The method for controlling ion beam sputtering as described in claim 4, characterized in that, When the current film formation rate is less than the first rate threshold or when the current film formation stress is less than the first stress threshold, the obtained bias pressure adjustment value is used to increase the bias pressure and update the normal operating value.

7. The method for controlling ion beam sputtering as described in claim 4, characterized in that, When the current film-forming stress is greater than the second stress threshold, the obtained bias pressure adjustment value is used to reduce the bias pressure and update the normal operating value.

8. The method for controlling ion beam sputtering as described in claim 4, characterized in that, When the current film formation rate is greater than the second rate threshold, the obtained beam pressure adjustment value is used to increase the beam pressure and update the normal operating value.

9. The method for controlling ion beam sputtering as described in claim 4, characterized in that, Obtain the current beam; When the current beam current is less than the minimum allowable beam current, the bias voltage adjustment value obtained by solving is used to increase the bias voltage and update the normal operating value.

10. The method for controlling ion beam sputtering as described in claim 1, characterized in that, A bias voltage circuit is configured at the target end to adjust the bias voltage; Configure an ion source to adjust the beam pressure; Configure a detection module to acquire the usage status, current film formation rate, and current film formation stress; A control module is configured and connected to the bias voltage circuit, ion source and detection module respectively, for obtaining the beam voltage adjustment value and / or the bias voltage adjustment value through the minimum objective function.

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