Ion source online detection method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention discloses an ion source online detection method and device, electronic equipment and a storage medium, and relates to the technical field of ion sources, and the method comprises the steps: receiving an ion beam emitted by an ion source, and obtaining a first current signal and a second current signal based on the ion beam measurement; the first current signal is measured by moving the Faraday cup along a horizontal axis, and the second current signal is measured by the Faraday cup under at least one bias voltage; performing inversion according to the first current signal and a space response function of the Faraday cup to obtain beam density distribution of the ion source; and / or, according to the second current signal and the spatial response function, performing inversion to obtain ion energy distribution of the ion source; the spatial response function is used for representing the probability that the ion beam is collected after entering the Faraday cup; and carrying out on-line detection on the ion source based on the beam density distribution and / or the ion energy distribution. The embodiment of the invention is suitable for carrying out online detection on the large-size ion source, the detection mode is simple, and the cost is relatively low.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of ion sources, and in particular, the present disclosure relates to an ion source online detection method and device, an electronic device and a storage medium. BACKGROUND

[0002] As a core component of ion beam processing, thin film deposition and surface modification equipment, the performance of the ion source directly determines the precision and stability of the process. For the processing and coating of high-precision and large-size workpieces, the ion source not only needs to provide stable beam output, but also must ensure uniform ion energy distribution and beam density distribution on the beam cross section at the workpiece position.

[0003] The existing ion source detection methods include probe detection method, optical emission spectroscopy method and Faraday cup measurement method; among them, the probe detection method will disturb the ion flow field, and the signal noise is large, which is not suitable for application in large-size and uniform beam field; the optical emission spectroscopy method has very high requirements for spectral resolution, and the measurement system is complex and expensive, usually needs special vacuum optical device support, and is difficult to apply in conventional process site; the Faraday cup measurement method can only measure the total current information, lacks the characterization ability of key parameters such as ion energy distribution, spatial distribution and beam divergence angle, and is difficult to meet the quantitative detection of beam uniformity and energy consistency of large-size ion source. How to detect large-size ion source at low cost has become a top priority. SUMMARY

[0004] The embodiments of the present disclosure provide an ion source online detection method, device, electronic device and storage medium, which can solve the technical problem of lack of low-cost online detection of large-size ion source in the prior art. The technical solutions provided by the present disclosure are as follows: According to a first aspect of the embodiments of the present disclosure, an ion source online detection method is provided, characterized in that the method is applied to a Faraday cup, and the method comprises: receiving an ion beam emitted by an ion source, and measuring a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along the horizontal axis, and the second current signal is measured under at least one bias voltage of the Faraday cup; inverting the beam density distribution of the ion source according to the first current signal and a spatial response function of the Faraday cup; and / or, inverting the ion energy distribution of the ion source according to the second current signal and the spatial response function; the spatial response function is used to characterize the probability of the ion beam being collected after being incident on the Faraday cup; performing online detection on the ion source based on the beam density distribution and / or the ion energy distribution.

[0005] As an optional implementation, the spatial response function of the Faraday cup is determined by: constructing an electric field vector distribution model of the Faraday cup, the electric field vector distribution model being used to determine the motion trajectory of ions in the ion beam in the Faraday cup; shooting ion beams with different divergence angles into the Faraday cup, and determining the probability of the ion beams with different divergence angles being collected by the Faraday cup based on the electric field vector distribution model; determining the spatial response function of the Faraday cup based on the probability of the ion beams with different divergence angles being collected by the Faraday cup.

[0006] As an optional implementation, the method further comprises, before the step of inversing the beam current density distribution based on the first current signal and the spatial response function: determining a first width of current broadening in the first current signal based on the first current signal; determining an average divergence angle of the ion beam based on the first width and a geometric distance from the Faraday cup to the ion source; determining a spatial response function corresponding to the average divergence angle based on the average divergence angle.

[0007] As an optional implementation, the step of inversing the beam current density distribution based on the first current signal and the spatial response function comprises: the first current signal being obtained by convolving the beam current density distribution with the spatial response model corresponding to the average divergence angle; obtaining the beam current density distribution by deconvolution operation based on the first current signal and the spatial response function corresponding to the average divergence angle.

[0008] As an optional implementation, the step of inversing the ion energy distribution of the ion source based on the second current signal and the spatial response function comprises: determining a second current signal measured by the Faraday cup at each bias voltage; the second current signal being obtained by convolving the ion energy distribution with the spatial response model; obtaining the ion energy distribution by deconvolution operation based on the second current signal and the spatial response function corresponding to the average divergence angle.

[0009] As an optional implementation, the method further comprises, after the step of inversing the ion energy distribution of the ion source based on the second current signal and the spatial response function: deriving the energy distribution function of the Faraday cup by differentiating the second current signal with respect to the bias voltage for each bias voltage; integrate the energy distribution in a two-dimensional space of the ion source, and compare the integral result with an energy distribution function of the Faraday cup on an energy point by energy point basis; if the comparison error is greater than a preset threshold, re-inverting the energy distribution.

[0010] As an optional implementation, the online detection of the ion source based on the beam current density distribution and / or the ion energy distribution includes: detecting the beam current uniformity of the ion source based on the beam current density distribution; and / or, detecting the energy consistency of the ion source based on the ion energy distribution.

[0011] According to a second aspect of the embodiments of the present disclosure, an ion source online detection device is provided, which is applied to a Faraday cup, and includes: a first processing module configured to receive an ion beam emitted by an ion source, and measure a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along a horizontal axis, and the second current signal is measured under at least one bias voltage of the Faraday cup; a second processing module configured to inversely obtain a beam current density distribution of the ion source according to the first current signal and a spatial response function of the Faraday cup; and / or, inversely obtain an ion energy distribution of the ion source according to the second current signal and the spatial response function; the spatial response function is used to represent a probability of the ion beam being collected after being incident to the Faraday cup; a third processing module configured to perform online detection of the ion source based on the beam current density distribution and / or the ion energy distribution.

[0012] According to a third aspect of the embodiments of the present disclosure, an electronic device is provided, which includes a memory, a processor, and a computer program stored in the memory, and the processor executes the computer program to implement the steps of the method according to any one of the first aspect.

[0013] According to a fourth aspect of the embodiments of the present disclosure, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps of the method according to any one of the first aspect.

[0014] The technical scheme provided by the embodiments of the present disclosure has the following beneficial effects: Embodiments of the present disclosure provide an ion source online detection method and device, electronic equipment and storage medium. Embodiments of the present disclosure are based on a common Faraday cup, and the beam current density distribution, divergence angle and energy distribution of the ion source are obtained by inversion. The large-size ion source can be monitored online or verified under actual process conditions, which provides a reliable basis for subsequent process parameter optimization and ion source regulation, and helps to improve the consistency and controllability of coating and etching processes. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments of the present disclosure will be briefly introduced.

[0016] Figure 1 A structural schematic diagram of a Faraday cup provided by an embodiment of the present disclosure is shown in FIG. 1. Figure 2 A flowchart of an ion source online detection method provided by an embodiment of the present disclosure is shown in FIG. 2. Figure 3 A schematic diagram of an ion beam entering a Faraday cup provided by an embodiment of the present disclosure is shown in FIG. 3. Figure 4 A schematic diagram of a spatial response function corresponding to ion beams with different divergence angles provided by an embodiment of the present disclosure is shown in FIG. 4. Figure 5 A structural schematic diagram of an ion source online detection device provided by an embodiment of the present disclosure is shown in FIG. 5. Figure 6 A structural schematic diagram of an electronic device provided by an embodiment of the present disclosure is shown in FIG. 6. DETAILED DESCRIPTION

[0017] Embodiments of the present disclosure will be described below in conjunction with the drawings in the present disclosure. It should be understood that the embodiments described below in conjunction with the drawings are exemplary descriptions of the technical solutions of the embodiments of the present disclosure, and do not limit the technical solutions of the embodiments of the present disclosure.

[0018] Those skilled in the art can understand that the singular forms "a," "an," and "the" used herein include plural forms unless otherwise stated. It should be further understood that the terms "include" and "contain" used in the embodiments of the present disclosure mean that the corresponding features can be implemented as the presented features, information, data, steps, operations, elements and / or components, but do not exclude other features, information, data, steps, operations, elements, components and / or their combinations supported by the present technology. It should be understood that when we say that an element is "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or it can mean that the element and the other element establish a connection relationship through an intermediate element. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The term "and / or" used herein indicates that at least one of the items defined by the term, for example, "A and / or B" or "A, B" indicates implementation as "A", or implementation as "B", or implementation as "A and B".

[0019] For the purpose, technical solutions and advantages of the present disclosure to be clearer, the embodiments of the present disclosure will be described in further detail below with reference to the drawings.

[0020] The existing ion source detection methods include probe detection method, optical emission spectroscopy method and Faraday cup measurement method. The probe detection method will disturb the ion flow field and has large signal noise, and is not suitable for application in large size and uniform beam field scenarios. The optical emission spectroscopy method has very high requirements for spectral resolution, and the measurement system is complex and expensive, and usually needs special vacuum optical devices to support, which is difficult to apply in conventional process field. The Faraday cup measurement method can only measure the total current information, and lacks the characterization ability of ion energy distribution, spatial distribution, beam divergence angle and other key parameters, and it is difficult to meet the quantitative demand for large area beam uniformity and energy consistency. Therefore, it is urgent to detect large size ion source at a lower price.

[0021] The ion source online detection method, device, electronic equipment and storage medium provided by the present disclosure aim to solve at least one of the above technical problems of the prior art.

[0022] The technical solutions of the embodiments of the present disclosure and the technical effects produced by the technical solutions of the present disclosure will be described below through the description of several exemplary embodiments. It should be pointed out that the following embodiments can be mutually referenced, borrowed or combined. For the same terms, similar features and similar implementation steps in different embodiments, they will not be described repeatedly.

[0023] Figure 1 A structural schematic diagram of a Faraday cup provided by the embodiments of the present disclosure is shown in FIG. 1. Figure 1As shown, the Faraday cup includes: a shielding cover 1, an entrance slit 2, a suppression electrode 3, a collection electrode 4, an insulating shell 5 and a bottom insulating support 6. Among them, the shielding cover 1 is used to shield the interference of external electric field and magnetic field, to ensure the accuracy of measurement; the entrance slit 2 is the entrance channel of the ion beam, used to control the incident range of the ion beam; the suppression electrode 3 is used to prevent secondary electrons from escaping, to improve the efficiency and accuracy of ion detection; the collection electrode 4 is used to collect incident ions, to convert the ion current into a measurable electrical signal; the insulating shell 5 insulates the collection electrode from the external structure, to avoid the influence of leakage on measurement; the bottom insulating support 6 is used to support the collection electrode and ensure its insulating performance, to maintain the structural stability of the Faraday cup.

[0024] Figure 2 A flowchart of an ion source online detection method provided by the embodiment of the present disclosure is shown in Figure 1. Figure 2 As shown, the method comprises: S201, receiving an ion beam emitted by an ion source, and measuring a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along the horizontal axis, and the second current signal is measured under at least one bias voltage of the Faraday cup.

[0025] Specifically, in the embodiment of the present disclosure, the Faraday cup receives an ion beam emitted by an ion source, which has a specific energy and intensity; by moving the Faraday cup along the horizontal axis, the ion beam is measured at different horizontal axis positions to obtain a first current signal, which is a curve of the current signal measured by the Faraday cup changing with the horizontal axis coordinate; and the second current signal is measured under the condition that at least one bias voltage is applied to the Faraday cup, and by setting different bias voltages, the current characteristics of the ion beam in different electric field environments, such as the energy distribution, charge state and other related information of the ions, can be studied.

[0026] Figure 3 A schematic diagram of an ion beam entering a Faraday cup provided by the embodiment of the present disclosure is shown in Figure 2. Figure 3 As shown, an ion source is arranged in front of the Faraday cup, the Faraday cup moves along the horizontal axis direction, and the ion beam emitted by the ion source enters the Faraday cup at different beam divergence angles, and the current signal measured by the Faraday cup during the movement along the horizontal axis direction is taken as the first current signal.

[0027] Specifically, in the embodiment of the present disclosure, the suppression electrode 3 of the Faraday cup can be connected to an adjustable positive bias voltage to form a deceleration electric field. When the ion beam enters the Faraday cup, the ions with energy lower than the energy threshold corresponding to the bias voltage will be decelerated or deflected and cannot reach the innermost collection electrode, but will be intercepted by the suppression electrode 3, and the current signal measured by the Faraday cup at this time is taken as the second current signal.

[0028] S202, obtaining the beam current density distribution of the ion source according to the first current signal and a spatial response function of the Faraday cup; and / or, obtaining the ion energy distribution of the ion source according to the second current signal and the spatial response function; the spatial response function is used to characterize the probability of the ion beam being collected after being incident on the Faraday cup.

[0029] Specifically, in the embodiments of the present disclosure, the first current signal is measured by the Faraday cup when moving along the transverse axis, which contains the current change information of the ion beam in the transverse axis direction; and the spatial response function of the Faraday cup is used to characterize the probability of the ion beam being collected after being incident on the Faraday cup, which reflects the collection characteristics of the Faraday cup for ion beams at different spatial positions. By performing inversion operation on the first current signal and the spatial response function, the distribution of the beam current density of the ion beam emitted by the ion source in space can be analyzed from the current signal, for example: the intensity difference of the ion beam in each region can be determined, which provides intuitive and accurate basis for evaluating the beam uniformity and beam focusing performance of the ion source.

[0030] Specifically, in the embodiments of the present disclosure, the second current signal is measured by the Faraday cup under at least one bias voltage, which is closely related to the energy characteristics of the ions; and by performing inversion operation on the spatial response function used to characterize the ion collection probability, the energy distribution of the ions emitted by the ion source can be derived from the second current signal, including the range of ion energy, the position of peak energy and the degree of energy dispersion, which is of great significance for judging the energy stability of the ion source and the effectiveness of the ion acceleration or ionization process.

[0031] S203, performing online detection on the ion source based on the beam current density distribution and / or the ion energy distribution.

[0032] Specifically, in the embodiments of the present disclosure, the beam current density distribution can be used to intuitively grasp the intensity distribution of the ion beam in space, for example: whether there is abnormal distribution of local over-density or over-sparse of the ion beam can be found in time, which is crucial for judging the beam uniformity of the ion source; at the same time, based on the ion energy distribution, the energy range and energy concentration degree of the ions in the ion beam can be accurately obtained, which can be used to evaluate the energy stability of the ion source, such as judging whether the ion source has the problem of energy drift or excessive energy dispersion. When the beam current density distribution and the ion energy distribution are combined for joint detection, the working state of the ion source can be comprehensively analyzed from two dimensions of the spatial distribution and the energy characteristics of the ions, realizing multi-parameter and all-around online diagnosis of the ion source.

[0033] In the embodiments of the present disclosure, based on the current signal measured by the Faraday cup, the beam current spatial distribution, the divergence angle and the energy distribution of the ion source are obtained by inversion, the online monitoring or process verification of the large-size ion source can be realized, reliable basis is provided for subsequent process parameter optimization and ion source regulation, and the consistency and controllability of the coating and etching process are improved.

[0034] On the basis of the above embodiments, as an optional embodiment, the spatial response function of the Faraday cup is determined by the following method: A model of the electric field vector distribution of the Faraday cup is constructed, and the model is used to determine the motion trajectory of the ions in the ion beam in the Faraday cup; The ion beams with different divergence angles are injected into the Faraday cup, and the probabilities of the ion beams with different divergence angles being collected by the Faraday cup are determined based on the model of the electric field vector distribution; The spatial response function of the Faraday cup is determined based on the probabilities of the ion beams with different divergence angles being collected by the Faraday cup.

[0035] Specifically, in the embodiments of the present disclosure, the Faraday cup is usually made of metal, and the shape and size of the Faraday cup will affect the distribution of the electric field. After determining the charge distribution, numerical calculation methods such as finite element analysis may be needed; modeling adopts a combination of electromagnetic finite element and charged particle tracking. First, the electrostatic potential distribution of the space inside and around the Faraday cup is solved by using the finite element method (FEM), considering the boundary conditions such as the collection electrode, the suppression electrode and the ground shield, to obtain the electric field vector distribution. Then, the initial energy, angle distribution and space charge effect of the charged particles are introduced, and the quasi-particle method (Quasi-PIC) or Monte Carlo particle tracking algorithm is used to simulate the motion trajectory and terminal landing point of the ions in the electric field, and the proportion of particles captured by the collection electrode is recorded.

[0036] Specifically, in the embodiments of the present disclosure, the spatial response function is essentially a quantitative description of the ion collection ability of the Faraday cup in different spatial directions, and the collection probability data provides a direct basis for determining this quantitative relationship. Ion beams with different divergence angles represent ions incident on the Faraday cup from different spatial directions. If the ion beam collection probability in a certain direction is high, it indicates that the Faraday cup has strong ion collection ability in that direction, and the response value corresponding to the direction in the spatial response function is also large. Conversely, if the ion beam collection probability in a certain direction is low, the response value of the direction in the spatial response function will be small. Therefore, the distribution of the collection probability directly determines the shape and characteristics of the spatial response function, and the spatial response function is calculated by numerically integrating the collection probability.

[0037] Figure 4A schematic diagram of a spatial response function corresponding to an ion beam with different divergence angles is provided in an embodiment of the present disclosure; as shown in Figure 4 The working distance WD between the ion source and the Faraday cup is equal to 100 mm; the horizontal axis coordinate is used to represent the position of the ion entering the Faraday cup, with the unit of mm; wherein the position of the Faraday center point is set to 0, the position to the left of the center point is negative, and the position to the right of the center point is positive; the vertical coordinate is the probability of the ion being collected by the Faraday cup, with the minimum value of 0, which is used to represent that the ion entering the Faraday cup has a probability of 0 of being collected by the Faraday cup; and the maximum value is 1, which is used to represent that the ion entering the Faraday cup has a probability of 1 of being collected by the Faraday cup.

[0038] Specifically, in an embodiment of the present disclosure, the divergence angle of the ion beam determines the distribution of the angle between the incident ion trajectory and the axis of the Faraday cup. As the divergence angle increases, the distribution of the incident ion in the cup opening area tends to spread, and part of the ion may not be collected or generate secondary electrons on the cup wall due to the too large incident angle, thereby causing the peak value of the spatial response function to decrease and the half-width to increase. Figure 4 It can be seen that as the divergence angle increases from 0.1° to 5°, the peak value of the probability of the ion beam being collected by the Faraday cup gradually decreases, and the half-width gradually increases.

[0039] It should be noted that the spatial response function is usually obtained by using an idealized model (such as a Gaussian distribution or a rectangular function) or by interpolation through a limited number of calibration points, and cannot completely reproduce the real response. Subsequently, through the inversion of the spatial response function to the beam current density distribution and the energy distribution, a certain error will inevitably be introduced.

[0040] In an embodiment of the present disclosure, by constructing an electric field vector distribution model of the Faraday cup, the motion trajectory of the ion in the electric field of the Faraday cup can be accurately simulated, the probability of the ion beam entering the Faraday cup after being collected under different divergence angles can be determined, the spatial response function can be determined based on these probabilities, and the response ability of the Faraday cup to different spatial distribution ion beams can be clearly reflected, thereby providing key technical support for the inversion of the beam current density distribution and the energy distribution of the ion source.

[0041] On the basis of the above embodiments, as an optional embodiment, before the beam current density distribution is obtained by inverting the first current signal and the spatial response function, the method further includes: determining a first width of current broadening in the first current signal based on the first current signal; determining an average divergence angle of the ion beam based on the first width and a geometric distance from the Faraday cup to the ion source; determining a spatial response function corresponding to the average divergence angle based on the average divergence angle.

[0042] Specifically, in the embodiments of the present disclosure, a linear geometric model of the ion source and the Faraday cup is constructed, the exit center of the ion source is set as the origin O, the receiving center of the Faraday cup is set as point P, and the linear distance between the two points is the geometric distance L. At this time, the first width corresponds to the spread of the first current signal, which is essentially the spatial projection width of the ion beam after passing a distance L, denoted as Δx. Assuming that the ion beam is emitted from the ion source with an average divergence angle θ, the projection width Δx formed by the ion beam on the receiving surface of the Faraday cup satisfies the trigonometric function relationship with the geometric distance L.

[0043] Specifically, in the embodiments of the present disclosure, the first width can be half of the spread of the first current signal, for example: performing feature analysis on the curve of the first current signal, eliminating signal noise through Gaussian fitting or polynomial fitting, then locating the peak current of the curve, taking 50% of the peak current as the threshold, finding the two transverse positions corresponding to the threshold (left boundary) and (right boundary), then the full width of the spread of the first current signal is ; the half width of the spread of the first current signal is ; that is .

[0044] Specifically, in the embodiments of the present disclosure, the average divergence angle can be calculated by the following formula:

[0045] wherein, is the average divergence angle of the ion beam.

[0046] Specifically, in the embodiments of the present disclosure, after determining the average divergence angle, the corresponding spatial response function can be determined based on the average divergence angle, for example: the calculated average divergence angle is 1°, then the spatial response function corresponding to the divergence angle of 1° can be found from Figure 4 , and the beam density distribution and energy distribution are inversed according to the spatial response function.

[0047] In the embodiments of the present disclosure, the beam density inversion is essentially the inverse problem of deriving infinite spatial distribution from limited current signal. Without additional constraints, multiple solutions may occur (such as different width beam density distributions corresponding to the same current signal), resulting in unstable results. The average divergence angle as a physical constraint condition can narrow the range of inversion solutions.

[0048] On the basis of the above embodiments, as an optional embodiment, the beam density distribution is inversed based on the first current signal and the spatial response function, comprising: The first current signal is obtained by convolving the spatial response model corresponding to the beam density distribution and the average divergence angle; Based on the first current signal and the spatial response function corresponding to the average divergence angle, the beam current density distribution is obtained by deconvolution operation.

[0049] Specifically, in the embodiments of the present disclosure, the first current signal measured by the Faraday cup is obtained by convolution of the beam current density distribution and the spatial response function, and the formula for convolution calculation is as follows:

[0050] wherein, is the position coordinate on the Faraday cup, is the position coordinate on the ion source, The ions incident on the Faraday cup are collected and the current signal is measured; is the position coordinate on the ion source, represents the beam current density distribution of the ion source, which is related to the spatial coordinates of the ions and the energy E of the ions; represents the spatial response function of the Faraday cup, reflecting the probability of collecting ions with different position coordinates and different energy E of the ion source into the Faraday cup.

[0051] Specifically, in the embodiments of the present disclosure, the shield 1 and the suppression electrode 3 in the Faraday cup Figure 1 can be grounded, the collector 4 can be connected to a negative bias, and the second current signal measured by the collector 4 and the moving Faraday cup and the spatial response function are used to obtain the beam current density distribution of the ion source, and the calculation formula of the beam current density distribution is as follows:

[0052] wherein, is a regularization parameter used to suppress numerical ill-posedness in the inversion process, and is generally taken as 0.001-0.1 in engineering. By iterative solution (such as Tikhonov regularization or iterative shrinkage threshold algorithm), the beam current density distribution of the ion source can be obtained.

[0053] It should be noted that, is a least squares term, which makes the "theoretically calculated current distribution" as close as possible to the "actually measured current distribution", minimizes the sum of squared residuals, and ensures the data consistency of the inversion result. is a regularization term used to solve the ill-posedness of the inversion problem.

[0054] In the embodiments of the present disclosure, the beam current density distribution of the ion source is obtained by Faraday cup inversion, which is suitable for quantitative analysis of the beam stability and uniformity of large-size ion sources in actual process, and effectively reduces the detection cost of large-size ion sources.

[0055] Based on the above embodiments, as an optional embodiment, the step of inverting the ion energy distribution of the ion source according to the second current signal and the spatial response function includes: Determine the second current signal measured by the Faraday cup under each bias voltage; the second current signal is obtained by convolving the ion energy distribution with the spatial response model. The ion energy distribution is obtained by deconvolution operation based on the second current signal and the spatial response function corresponding to the average divergence angle.

[0056] Specifically, in this embodiment of the disclosure, the Faraday cup employs a multilayer electrode structure, wherein the electrodes located in the middle layer (corresponding to...) Figure 1 The suppressor electrode 3 can be connected to an adjustable positive bias voltage to create a decelerating electric field. When the ion beam enters the Faraday cup, ions with energies lower than the energy threshold corresponding to this bias voltage will be decelerated or deflected, preventing them from reaching the innermost collecting electrode and instead being captured by the suppressor electrode 3. This can be achieved by gradually changing the bias voltage. This allows for the selective separation of ions with different energy levels.

[0057] Specifically, in this embodiment of the disclosure, the energy corresponding to each bias voltage Under this bias, the current distribution measured by the Faraday cup can be obtained. By distributing the current Differentiating the bias voltage yields the current signal of the ion at energy E. , The calculation formula is as follows:

[0058] Specifically, in this embodiment of the disclosure, the current signal of the ion at energy E Equal to the coordinate position of the ion Energy distribution With spatial response function Convolution, the formula for calculating convolution is shown below:

[0059] It should be noted that the spatial response function Obtained using an approximation model, and its... The convolution result cannot perfectly match the real current. Therefore, the above convolution formula needs to use an approximate equality sign to reflect this "model approximation".

[0060] Specifically, in this embodiment of the disclosure, the energy distribution is obtained by performing deconvolution calculation on the above convolution formula. Thus, the ion energy distribution in space is accurately inversed, and a two-dimensional energy distribution map, i.e., the distribution characteristics of ion energy at different spatial positions, is obtained. Not only the energy uniformity of the ion source in different regions can be distinguished, but also the stability of the ion source electric field, the acceleration system and the neutralizer operation state can be judged, thereby providing a quantitative basis for ion source debugging and process optimization.

[0061] In the embodiments of the present disclosure, the energy distribution of the ion source is obtained by Faraday cup inversion, which is suitable for quantitative analysis of the energy consistency of a large-size ion source under actual process, and effectively reduces the detection cost of the large-size ion source.

[0062] On the basis of the above embodiments, as an optional embodiment, after the ion energy distribution of the ion source is inversed according to the second current signal and the spatial response function, the method further comprises: Deriving the second current signal with respect to the change of the bias voltage to obtain an energy distribution function of the Faraday cup for each bias voltage; Integrating the energy distribution in the two-dimensional space of the ion source, and comparing the integration result with the energy distribution function of the Faraday cup point by point; If the comparison error is greater than a preset threshold, the energy distribution is inversed again.

[0063] Specifically, in the embodiments of the present disclosure, under each bias voltage setting, the current collected by the suppressor 3 is measured Deriving the current with respect to the change of the bias voltage, the ion energy distribution function , The calculation formula of the ion energy distribution function is as follows:

[0064] Wherein, is the ion charge.

[0065] Specifically, in the embodiments of the present disclosure, the ions corresponding to a certain energy E are only distributed in different spatial positions of the beam, and cannot be generated or disappeared in the air. Therefore, the ion energy distribution function is integrated in the two-dimensional space of the ion source, and the total intensity after integration is consistent with the ion energy distribution function If they are not consistent, it means that the inversion result violates the "particle number / energy conservation", and there is an error.

[0066] Specifically, in the embodiments of the present disclosure, the energy distribution is integrated in the two-dimensional space of the ion source, and the integration formula is as follows:

[0067] Specifically, in the embodiments of the present disclosure, the integral result is compared with the energy distribution function of the Faraday cup at each energy point, and the relative error is calculated. The calculation formula of the relative error is as follows:

[0068] wherein, is the relative error at energy E; when is less than or equal to a preset threshold, it indicates that the energy distribution obtained by inversion is accurate; otherwise, if the relative error is greater than the preset threshold, it indicates that the energy distribution obtained by inversion is inaccurate, and the energy distribution needs to be re-inverted.

[0069] Specifically, in the embodiments of the present disclosure, the common causes of error exceeding the standard include but are not limited to: inaccurate calibration of the spatial response function, local current signal noise, and unreasonable regularization parameters of the inversion algorithm, so the error can be corrected by re-inversion. For example, if the error is caused by the response function deviation, the response function can be calibrated again using a standard ion beam, and then re-inverted; if the error is caused by noise, the number of measurements of the local current signal can be increased, and the noise can be smoothed and then recalculated.

[0070] In the embodiments of the present disclosure, the relative error can be calculated to gradually reduce the deviation of the inversion result, and finally output the two-dimensional energy distribution that meets the accuracy requirement, thereby effectively improving the accuracy of the inversion result.

[0071] On the basis of the above embodiments, as an optional embodiment, the ion source is detected online based on the beam current density distribution and / or the ion energy distribution. Based on the beam current density distribution, the beam current uniformity of the ion source is detected; and / or, based on the ion energy distribution, the energy consistency of the ion source is detected.

[0072] Specifically, in the embodiments of the present disclosure, the obtained beam current density distribution can be used to calculate the beam current uniformity index. For example, the maximum value , the minimum value and the average value of the beam current density can be determined, and the beam current uniformity bias and the standard deviation normalization index can be calculated according to the maximum value, the minimum value and the average value of the beam current density distribution; through these indexes, the uniformity of the ion source on a large-area workpiece can be quantitatively evaluated.

[0073] Specifically, in the embodiments of the present disclosure, the calculation formula of the beam current uniformity bias is as follows:

[0074] Specifically, in the embodiments of the present disclosure, the calculation formula of the standard deviation normalization index The calculation formula is as follows:

[0075] N represents the total number of samples participating in the calculation, that is, the number of beam current density participating in the formula calculation; for example, the beam current density distribution is sampled 100 times to obtain 100 discrete beam current density values, and N is equal to the total number of samples 100.

[0076] Specifically, in the embodiments of the present disclosure, the energy consistency of the ion source can be detected according to the energy distribution. For example, if the density of a certain point in the energy distribution is significantly higher or lower than the adjacent region, it can be determined that the ion source filament discharge, local damage or pollution of the component causes the abnormality. If the density fluctuation of the same position in multiple scans exceeds the preset threshold (such as > 5%), it can be determined that the ion source is unstable or the power supply drifts. If the energy distribution curve has an abnormal peak value, it can be used to judge the unevenness of the plasma inside the ion source or the mixing of impurity ions.

[0077] In the embodiments of the present disclosure, the ion source is detected online through the beam current density distribution and the energy distribution, which not only improves the accuracy and efficiency of the ion source state monitoring, but also provides a key guarantee for the stability of subsequent ion beam processing, ultimately reduces the processing cost and improves the processing yield of optical elements.

[0078] Figure 5 A structure diagram of an ion source online detection device provided in the embodiments of the present disclosure is shown in FIG. 1, which includes a first processing module 5001, a second processing module 5002 and a third processing module 5003. Wherein: Figure 5 The first processing module 5001 is configured to receive the ion beam emitted by the ion source, and measure a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along the horizontal axis, and the second current signal is measured under at least one bias voltage. The second processing module 5002 is configured to obtain the beam current density distribution of the ion source by inversion according to the first current signal and the spatial response function of the Faraday cup; and / or, obtain the ion energy distribution of the ion source by inversion according to the second current signal and the spatial response function; the spatial response function is used to characterize the probability of the ion beam being collected after being incident on the Faraday cup. The third processing module 5003 is configured to perform online detection on the ion source based on the beam current density distribution and / or the ion energy distribution.

[0079] ​The ion source online detection device provided by the embodiments of the present disclosure can execute the ion source online detection method provided by the embodiments of the present disclosure, and the implementation principles are similar. The actions performed by each module in the ion source online detection device provided by the embodiments of the present disclosure correspond to the steps in the ion source online detection method provided by the embodiments of the present disclosure. For the detailed function description of each module of the ion source online detection device provided by the embodiments of the present disclosure, refer to the description in the corresponding method shown in the foregoing, which will not be repeated here.

[0080] The embodiments of the present disclosure are based on a common Faraday cup, and the beam current density distribution, divergence angle and energy distribution of the ion source are obtained by inversion. The large-size ion source can be monitored or verified in the actual process conditions, which provides a reliable basis for subsequent process parameter optimization and ion source regulation, and helps to improve the consistency and controllability of the coating and etching processes.

[0081] Figure 6 A structural schematic diagram of an electronic device provided by the embodiments of the present disclosure is shown in FIG. 4, which includes a processor 4001 and a memory 4003. The processor 4001 and the memory 4003 are connected, for example, through a bus 4002. Optionally, the electronic device 4000 can further include a transceiver 4004, which can be used for data interaction between the electronic device and other electronic devices, such as data transmission and / or data reception. It should be noted that the transceiver 4004 is not limited to one in actual application, and the structure of the electronic device 4000 does not constitute a limitation on the embodiments of the present disclosure. Figure 6

[0082] The processor 4001 can be a CPU (Central Processing Unit, central processing unit), a general-purpose processor, a DSP (Digital Signal Processor, data signal processor), an ASIC (Application Specific Integrated Circuit, application specific integrated circuit), an FPGA (Field Programmable Gate Array, field programmable gate array) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can realize or execute various exemplary logical blocks, modules and circuits described in combination with the present disclosure. The processor 4001 can also be a combination of computing functions, such as one or more microprocessor combinations, DSP and microprocessor combinations, etc.

[0083] ​The bus 4002 can include a path that transmits information between the above-described components. The bus 4002 can be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, or the like. The bus 4002 can be divided into an address bus, a data bus, a control bus, or the like. For convenience of representation, Figure 4 In the drawing, only one thick line is shown, but this does not mean that there is only one bus or only one type of bus.

[0084] The memory 4003 can be a ROM (Read Only Memory) or other type of static storage device that can store static information and instructions, a RAM (Random Access Memory) or other type of dynamic storage device that can store information and instructions, an EEPROM (Electrically Erasable Programmable Read Only Memory), a CD-ROM (Compact Disc Read Only Memory) or other optical disk storage, a magnetic disk storage medium, other magnetic storage device, or any other medium that can be used to carry or store computer programs and that can be read by a computer, without limitation.

[0085] The memory 4003 is used to store a computer program for implementing the embodiments of the present disclosure, and is controlled by the processor 4001 to perform. The processor 4001 is used to execute the computer program stored in the memory 4003 to realize the steps shown in the foregoing method embodiments.

[0086] The electronic device package can include, but is not limited to, mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Tablet PCs), PMPs (Portable Multimedia Players), vehicle terminals (for example, car navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like. Figure 4 The electronic device shown is only an example and should not limit the functions and use range of the embodiments of the present disclosure.

[0087] The embodiments of the present disclosure provide a computer readable storage medium, and the computer readable storage medium stores a computer program. When the computer program is executed by a processor, the steps and corresponding contents of the foregoing method embodiments can be realized.

[0088] It should be noted that the computer readable medium in the foregoing of the present disclosure can be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium may, for example, be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or apparatus, or any suitable combination of the above. More specific examples of the computer readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus or device. In the present disclosure, the computer readable signal medium can include a data signal carried in a baseband or as a part of a carrier wave, which carries computer readable program code. Such a propagated data signal can take many forms, including but not limited to, an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer readable signal medium can also be any computer readable medium that can send, propagate or transfer a program for use by or in connection with an instruction execution system, apparatus or device. The program code contained on the computer readable medium can be transmitted using any suitable medium, including but not limited to, wire, cable, RF (radio frequency), etc., or any suitable combination of the above.

[0089] The present disclosure also provides a computer program product comprising a computer program, which, when executed by a processor, can implement the steps and corresponding contents of the foregoing method embodiments. Compared with the prior art, the following can be achieved: The terms "first", "second", "third", "fourth", "1", "2", etc. (if any) in the specification and claims of the present disclosure and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present disclosure described herein can be implemented in an order other than that shown or described.

[0090] It should be understood that although the various operation steps in the flowcharts of the embodiments of the present disclosure are indicated by arrows, the implementation order of the steps is not limited to the order indicated by the arrows. Unless otherwise specified herein, in some implementation scenarios of the embodiments of the present disclosure, the implementation steps in each flowchart can be executed in other orders as required. In addition, part or all of the steps in each flowchart can include multiple sub-steps or multiple stages based on the actual implementation scenario. Part or all of these sub-steps or stages can be executed at the same time, and each of these sub-steps or stages can also be executed at different times. In the scenario where the execution times are different, the execution order of these sub-steps or stages can be flexibly configured as required, and the embodiments of the present disclosure do not limit this.

[0091] The above is only an optional implementation of some implementation scenarios of the present disclosure, and it should be pointed out that, for ordinary skilled persons in the technical field, other similar implementation means based on the technical idea of the present disclosure without departing from the technical concept of the present disclosure also belong to the protection scope of the embodiments of the present disclosure.

Claims

1. An ion source on-line monitoring method, characterized by, The method is applied to a Faraday cup, and the method comprises: receiving an ion beam emitted by an ion source, and measuring a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along a transverse axis, and the second current signal is measured under at least one bias voltage of the Faraday cup; inverting a beam current density distribution of the ion source according to the first current signal and a spatial response function of the Faraday cup; and / or, inverting an ion energy distribution of the ion source according to the second current signal and the spatial response function; the spatial response function is used to characterize a probability of the ion beam being collected after being incident on the Faraday cup; performing online detection on the ion source based on the beam current density distribution and / or the ion energy distribution.

2. The method of claim 1, wherein the ion source is an inductively coupled plasma source. The spatial response function of the Faraday cup is determined by: constructing an electric field vector distribution model of the Faraday cup, the electric field vector distribution model being used to determine a motion trajectory of an ion in the ion beam in the Faraday cup; shooting ion beams with different divergence angles into the Faraday cup, and determining probabilities of the ion beams with different divergence angles being collected by the Faraday cup based on the electric field vector distribution model; determining the spatial response function of the Faraday cup based on the probabilities of the ion beams with different divergence angles being collected by the Faraday cup.

3. The method of claim 2, wherein the ion source is an inductively coupled plasma source. Before the inversion of the beam current density distribution based on the first current signal and the spatial response function, the method further comprises: determining a first width of current broadening in the first current signal based on the first current signal; determining an average divergence angle of the ion beam based on the first width and a geometric distance from the Faraday cup to the ion source; determining a spatial response function corresponding to the average divergence angle based on the average divergence angle.

4. The method of claim 3, wherein the ion source is an inductively coupled plasma source. The inversion of the beam current density distribution based on the first current signal and the spatial response function comprises: the first current signal is obtained by convolving the beam current density distribution and the spatial response function corresponding to the average divergence angle; and the beam current density distribution is obtained by deconvolution operation based on the first current signal and the spatial response function corresponding to the average divergence angle.

5. The method of claim 3, wherein the ion source is an inductively coupled plasma source. The inversion of the ion energy distribution of the ion source according to the second current signal and the spatial response function comprises: determining the second current signal measured by the Faraday cup under each bias voltage; the second current signal is obtained by convolving the ion energy distribution and the spatial response function; the ion energy distribution is obtained by deconvolution operation based on the second current signal and the spatial response function corresponding to the average divergence angle.

6. The method of claim 5, wherein the ion source is an inductively coupled plasma source. After the inversion of the ion energy distribution of the ion source according to the second current signal and the spatial response function, the method further comprises: deriving the second current signal with respect to the bias voltage to obtain an energy distribution function of the Faraday cup for each bias voltage; integrating the energy distribution in a two-dimensional space of the ion source, and comparing the integration result with the energy distribution function of the Faraday cup point by point in energy. If the comparison error is greater than a preset threshold, the energy distribution is re-inverted.

7. The method of claim 1-6, wherein, The ion source is detected on-line based on the beam current density distribution and / or the ion energy distribution. Beam current uniformity of the ion source is detected based on the beam current density distribution, and / or energy consistency of the ion source is detected based on the ion energy distribution.

8. An ion source on-line monitoring device, characterized by, The device is applied to a Faraday cup, and the device comprises: A first processing module is configured to receive an ion beam emitted by an ion source, and measure a first current signal and a second current signal based on the ion beam; the first current signal is measured by moving the Faraday cup along a horizontal axis, and the second current signal is measured under at least one bias voltage; A second processing module is configured to inversely obtain a beam current density distribution of the ion source according to the first current signal and a spatial response function of the Faraday cup, and / or inversely obtain an ion energy distribution of the ion source according to the second current signal and the spatial response function; the spatial response function is used to represent a probability that the ion beam is collected after being incident to the Faraday cup; A third processing module is configured to detect the ion source on-line based on the beam current density distribution and / or the ion energy distribution.

9. An electronic device comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program comprises instructions that, when executed by the processor, cause the electronic device to perform the method of any one of claims 1-8. The processor executes the computer program to implement the method in any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method in any one of claims 1 to 7.

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