Deflection coil control method, electron beam exposure machine, medium and product
By employing a combination of low-speed, high-precision and high-speed digital-to-analog converters in an electron beam exposure machine, and utilizing sub-field partitioning and collaborative control, the problem of balancing accuracy and speed in traditional electron beam exposure machines is solved, thereby improving the overall efficiency and pattern accuracy of the exposure machine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN ZEYOU TECH CO LTD
- Filing Date
- 2026-01-30
- Publication Date
- 2026-04-24
AI Technical Summary
Traditional digital-to-analog converters cannot simultaneously achieve both conversion accuracy and conversion rate, making it difficult to balance exposure accuracy and exposure rate during electron beam exposure, thus affecting processing efficiency.
By employing a combination of low-speed, high-precision digital-to-analog converters (DACs) and high-speed DACs, the preset write field is divided into sub-write fields. The low-speed, high-precision DAC enables precise positioning and switching of the electron beam, while the high-speed DAC enables efficient scanning exposure.
It achieves a balance between precision and speed in electron beam exposure, improves overall exposure efficiency, and ensures pattern accuracy and processing efficiency.
Smart Images
Figure CN121918360A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of electron beam exposure technology, specifically relating to a deflection coil control method, an electron beam exposure machine, a computer-readable storage medium, and a computer program product. Background Technology
[0002] Electron beam lithography (EBRT) boasts ultra-high pattern resolution, flexible layout adaptability, and the advantage of direct writing without masks, making it crucial in the field of micro- and nano-device fabrication. As the integration complexity of micro- and nano-devices continues to increase, EBRT needs to possess both high precision and high-speed production capabilities to meet manufacturing demands.
[0003] In the operation of an electron beam lithography machine, the deflection coil is a crucial component for controlling the landing position of the electron beam. The deflection coil generates a magnetic field to precisely deflect the electron beam trajectory. The digital-to-analog converter (DAC) is an important signal conversion component in the electron beam lithography machine, used to convert digital control signals into analog drive signals. The analog drive signal output by the DAC drives the deflection coil to generate a precise deflection magnetic field. The conversion accuracy and conversion rate of the DAC directly affect the deflection accuracy and deflection rate of the deflection coil.
[0004] Traditional DACs cannot simultaneously achieve both conversion accuracy and conversion rate, resulting in a situation where electron beam exposure processes cannot simultaneously achieve both exposure accuracy and exposure rate. Summary of the Invention
[0005] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a deflection coil control method, an electron beam exposure machine, a computer-readable storage medium, and a computer program product, which can balance the accuracy and rate of electron beam exposure and effectively improve the overall exposure efficiency.
[0006] In a first aspect, this application provides a deflection coil control method applied to an electron beam exposure machine. The electron beam exposure machine includes a first digital-to-analog converter (DAC), a second DAC, and a deflection coil. The conversion rate of the first DAC is lower than that of the second DAC, and the conversion accuracy of the first DAC is higher than that of the second DAC. The method includes: Obtain the reference coordinates of each sub-field of the preset writing field and the coordinates of each field to be exposed; The deflection parameters of the deflection coil are adjusted by the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinate of any target write field in each of the sub-write fields. After the electron beam is aligned with the reference point, the deflection coil is controlled by the second digital-to-analog converter to deflect the electron beam, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of each target writing field.
[0007] Secondly, this application provides an electron beam exposure machine, which includes a first digital-to-analog converter, a second digital-to-analog converter, a deflection coil, a processor, and a memory; The conversion rate of the first digital-to-analog converter is lower than that of the second digital-to-analog converter, and the conversion accuracy of the first digital-to-analog converter is higher than that of the second digital-to-analog converter. The first digital-to-analog converter and the second digital-to-analog converter are used to control the deflection coil. The memory stores a computer program, and the processor executes the deflection coil control method described above by calling the computer program stored in the memory.
[0008] Thirdly, this application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the aforementioned deflection coil control method.
[0009] Fourthly, this application provides a computer program product including computer instructions, which, when executed by a processor, implement the aforementioned deflection coil control method.
[0010] The deflection coil control method, electron beam exposure machine, computer-readable storage medium, and computer program product provided in this application divide a large preset write field into smaller sub-write fields, and obtain the reference coordinates and exposure coordinates of each sub-write field of the preset write field. Because the sub-write fields are smaller, even if the conversion accuracy of the second analog-to-digital converter is low, the electron beam after the deflection coil is deflected by the second analog-to-digital converter can maintain sufficient positioning accuracy in the sub-write fields.
[0011] The deflection parameters of the deflection coil are adjusted by the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinate of any target writing field in each sub-writing field. The first digital-to-analog converter has high conversion accuracy. The first digital-to-analog converter adjusts the deflection coil to realize the jumping positioning of the electron beam in different sub-writing fields, which can ensure the positioning accuracy of the electron beam in the entire preset writing field, while avoiding excessive consumption of time.
[0012] After the electron beam is aligned with the reference point of the target writing field, the deflection coil is controlled by the second digital-to-analog converter to deflect the electron beam, so that the deflected electron beam exposes each point of the target writing field to be exposed. The second analog-to-digital converter has a high conversion rate, so it can control the deflection coil to deflect the electron beam at a high conversion rate while ensuring the positioning accuracy of the electron beam, thereby improving the exposure efficiency.
[0013] In this way, both the accuracy and speed of electron beam exposure can be taken into account, effectively improving the overall exposure efficiency of the electron beam exposure machine.
[0014] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them: Figure 1 This is a first application scenario diagram of the deflection coil control method provided in the embodiments of this application; Figure 2 This is a second application scenario diagram of the deflection coil control method provided in the embodiments of this application; Figure 3 This is a first flowchart illustrating the deflection coil control method provided in this application embodiment; Figure 4 This is a schematic diagram of the preset write field of the deflection coil control method provided in the embodiments of this application; Figure 5 This is a second flowchart illustrating the deflection coil control method provided in the embodiments of this application; Figure 6 This is a third flowchart illustrating the deflection coil control method provided in the embodiments of this application; Figure 7 This is a fourth flowchart illustrating the deflection coil control method provided in the embodiments of this application; Figure 8 This is a fifth flowchart illustrating the deflection coil control method provided in the embodiments of this application; Figure 9 This is a first schematic diagram of line-by-line scanning exposure of the deflection coil control method provided in the embodiments of this application; Figure 10 This is a second schematic diagram of line-by-line scanning exposure of the deflection coil control method provided in the embodiments of this application; Figure 11 This is a sixth flowchart illustrating the deflection coil control method provided in the embodiments of this application; Figure 12 This is a schematic diagram of the control device for the deflection coil provided in the embodiments of this application; Figure 13 This is a schematic diagram of the electron beam exposure machine provided in the embodiments of this application. Detailed Implementation
[0016] The embodiments of this application are described in detail below. Examples of the embodiments of this application are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0017] In the description of this application, it should be understood that 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, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" 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 mechanical connection or an electrical 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 or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0019] To facilitate understanding, the background technology and application scenarios of this application will be introduced below: In traditional electron beam lithography machines, the digital-to-analog converters (DACs) used are typically either standalone high-speed DACs or low-speed, high-precision DACs. High-speed DACs are designed with dynamic conversion rate as the core objective, focusing on optimizing dynamic performance indicators such as settling time and conversion rate, and can quickly respond to high-frequency digital control commands. Low-speed, high-precision DACs are designed with static conversion accuracy as the core objective, focusing on optimizing static indicators such as integral nonlinearity (INL), differential nonlinearity (DNL), and output noise, and have a relatively lower conversion rate. The conversion rate of a low-speed, high-precision DAC is lower than that of a high-speed DAC, but its conversion accuracy is higher.
[0020] In traditional schemes that use high-speed DACs to control and drive deflection coils, the high-speed DAC directly outputs high-frequency drive signals to control the deflection coils to deflect the electron beam, which can meet the high-speed deflection scanning requirements of the electron beam. However, due to the integral nonlinearity error, differential nonlinearity error, and temperature drift of the high-speed DAC, significant nonlinear errors are easily generated during large-area field positioning, resulting in increased edge roughness and poor linewidth uniformity of the processed pattern, which seriously reduces the overall exposure accuracy.
[0021] In traditional schemes using a low-speed, high-precision DAC to control the deflection coil, the DAC directly outputs a high-precision drive signal to control the deflection coil and deflect the electron beam. This ensures high precision and low noise in the drive signal, meeting the high-precision scanning requirements of the electron beam. However, due to the narrow response bandwidth and low conversion rate of the DAC, it cannot quickly respond to high-frequency scanning commands, limiting the scanning speed of the electron beam and significantly reducing exposure efficiency. Especially when exposing large-area patterns, a significant amount of time is required to complete the deflection and positioning of the electron beam, resulting in low overall processing efficiency and difficulty in meeting production capacity demands.
[0022] Please see Figure 1 , Figure 1 This is an application scenario diagram of a deflection coil control method provided in an embodiment of this application. The application scenario provided in this application includes an electron beam exposure machine 100, which includes a control device 10, a first digital-to-analog converter 20, a second digital-to-analog converter 30, and a deflection coil 40. The deflection coil control method provided in this application can be executed by the control device 10.
[0023] The control device 10 is a control unit used to regulate the operating conditions of various components of the electron beam exposure machine 100. The control device 10 works in coordination with the various components of the electron beam exposure machine 100 to achieve precise control over the electron beam trajectory, beam current intensity, exposure dose, etc., to ensure the accuracy and efficiency of the entire exposure process of the device to be exposed 110.
[0024] Optionally, the control device 10 may include, but is not limited to, a microcontroller unit (MCU), a programmable logic controller (PLC), a dedicated integrated chip, a system on a chip (SoC), a field-programmable gate array (FPGA), etc., and the embodiments of this application do not limit this.
[0025] A digital-to-analog converter (DAC) is a device that converts discrete digital control signals into continuous analog drive signals. The DAC in the electron beam exposure machine 100 includes a first DAC 20 and a second DAC 30. The conversion rate of the first DAC 20 is lower than that of the second DAC 30, and the conversion accuracy of the first DAC 20 is higher than that of the second DAC 30.
[0026] In this embodiment, the first digital-to-analog converter 20 is a low-speed, high-precision DAC, and the second digital-to-analog converter 30 is a high-speed DAC. Optionally, the low-speed, high-precision DAC may include, but is not limited to, a sum-increment DAC (i.e., a Σ-Δ DAC), an R-2R resistor ladder network DAC, etc.; the high-speed DAC may include, but is not limited to, a current-driven DAC, a high-speed voltage output DAC, etc., and the embodiments of this application do not limit this.
[0027] The deflection coil 40 is a component used to control the deflection trajectory of the electron beam. The deflection coil 40 can be composed of multiple sets of electromagnetic coils wound on an iron core or ceramic frame. The deflection coil 40 generates a controllable deflection magnetic field based on the input current, thereby changing the trajectory and landing position of the electron beam. The deflection coil 40 is controlled by a digital-to-analog converter (DAC), precisely adjusting the magnitude of the input current according to the DAC's output signal.
[0028] Optionally, the deflection coil 40 may include, but is not limited to, electromagnetic deflection coils, electrostatic deflection coils, multi-pole deflection coils, etc., and the embodiments of this application do not limit this.
[0029] Optionally, the deflection coil 40 includes a lateral deflection coil and a longitudinal deflection coil; the lateral deflection coil is used to control the deflection of the electron beam in the lateral direction, and the longitudinal deflection coil is used to control the deflection of the electron beam in the longitudinal direction. On the plane where the device to be exposed 110 is located, the lateral direction and the longitudinal direction are orthogonal; for example, the lateral direction is the X-axis direction, and the longitudinal direction is the Y-axis direction, and the X-axis and Y-axis are orthogonal to form a Cartesian coordinate system.
[0030] In one alternative embodiment, please refer to Figure 2 The deflection coil 40 includes a first deflection coil 41 and a second deflection coil 42. The first deflection coil 41 is controlled by a first digital-to-analog converter 20, and the second deflection coil 42 is controlled by a second digital-to-analog converter 30. The first deflection coil 41 precisely adjusts the magnitude of the input current according to the output signal of the first digital-to-analog converter 20; the second deflection coil 42 precisely adjusts the magnitude of the input current according to the output signal of the second digital-to-analog converter 30.
[0031] Optionally, the electron beam exposure machine 100 also includes an electron gun 50, a focusing lens 60, a vacuum chamber 70, and a displacement stage 80. The electron gun 50 is used to generate a high-energy electron beam, providing an energy-controllable electron beam for the exposure process; the focusing lens 60 is used to focus the diverging electron beam generated by the electron gun 50 into a finer micro-beam to ensure the resolution of the exposed pattern; the vacuum chamber 70 is used to provide a high-vacuum environment for the transmission and exposure of the electron beam, avoiding problems such as beam scattering and energy attenuation caused by collisions between the electron beam and gas molecules, and ensuring the transmission stability and exposure accuracy of the electron beam; the displacement stage 80 is located in the vacuum chamber 70 and is used to support the device 110 to be exposed. By moving the displacement stage 80, the device 110 to be exposed can be moved with high precision, which can adapt to the scanning exposure and field stitching of the electron beam, ensuring the stitching accuracy of the overall pattern.
[0032] Optionally, the application scenarios provided in this application may also include a host computer 120, and the electron beam exposure machine may also include a pattern generator 90.
[0033] The host computer 120 is communicatively connected to the electron beam exposure machine 100. The host computer 120 can determine the coordinate data of each exposure point on the device to be exposed 110 based on the layout data and transmit it to the electron beam exposure machine 100. The host computer 120 can also transmit the layout data to the pattern generator 90, which can determine the coordinate data of each exposure point on the device to be exposed 110 based on the received layout data. The pattern generator 90 can also be used to convert the coordinate data of each exposure point into digital signals and transmit them to a digital-to-analog converter (DAC); for example, to a first DAC 20 and a second DAC 30, respectively.
[0034] Based on the above background technology and related scenarios, this application provides a control method for a deflection coil. The control method for the deflection coil will be described in detail below: Please see Figure 3 The deflection coil control method provided in this application embodiment is implemented by steps 011, 012 and 013, which are described in detail below.
[0035] Step 011: Obtain the reference coordinates of each sub-field of the preset writing field and the coordinates of each field to be exposed; The preset write field is a pre-planned specific area used to carry the exposure pattern; the sub-write field is a smaller write field resulting from the division of the preset write field. For example, please refer to... Figure 4The large area defined by the solid line frame is a preset write field. Divided evenly by four vertical and four horizontal dashed lines, the preset write field is further divided into 5 × 5 = 25 smaller areas of uniform size, each of which is a sub-write field. Points S1, S2, S3, S4, and S5 are the reference points corresponding to the reference coordinates of the five sub-write fields, and point A1-1 is the exposure point corresponding to the exposure coordinates within a sub-write field.
[0036] Optionally, the sub-write field is rectangular and located within the deflection range of the second digital-to-analog converter.
[0037] Specifically, the deflection range of the second digital-to-analog converter (DAC) is a rectangular region. Beyond this range lies the non-linear region, which can easily cause image distortion. The deflection range of the second DAC is determined by the linear output range of two orthogonal axes (horizontal and vertical). The maximum linear deflection lengths of the horizontal and vertical axes are orthogonal, jointly defining the rectangular region.
[0038] In this way, by ensuring that the size of the sub-write field is within the deflection range of the second DAC, it is possible to guarantee that the electron beam driven by the second DAC to deflect the deflection coil can achieve high-precision scanning in the sub-write field, thus avoiding nonlinear distortion.
[0039] Among them, the reference coordinates are the reference coordinates for determining the position and range of the sub-write field. For example, the coordinates corresponding to the center position (the intersection of the diagonals) of a rectangular sub-write field are the reference coordinates.
[0040] Specifically, this can be achieved by communicating with a host computer to obtain the reference coordinates and exposure coordinates of the preset write field. The host computer can then analyze the layout data to be exposed, determine the layout portion corresponding to the preset write field, and, based on the position of each sub-write field, calculate and generate the reference coordinates and exposure coordinates of each sub-write field within the preset write field, which are then transmitted to the electron beam exposure machine. Alternatively, the layout portion corresponding to the preset write field can be determined based on the acquired layout data, and then, based on the position of each sub-write field, the reference coordinates and exposure coordinates of each sub-write field within the preset write field can be calculated and generated.
[0041] Step 012: Adjust the deflection parameters of the deflection coil through the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinates of any target writing field in each sub-writing field. The reference point can be the center of the target field of the rectangle, that is, the intersection of the diagonals of the rectangle.
[0042] Specifically, the reference coordinates of the target write field are converted into digital signals, which are then input into a first digital-to-analog converter (DAC). The first DAC outputs a corresponding analog drive signal to the deflection coil, thereby adjusting the deflection parameters of the deflection coil. After the first DAC has adjusted the deflection parameters of the deflection coil for a preset time (based on empirical settings), it is determined that the first DAC has completed the adjustment of the deflection coil. In this case, if an electron beam passes through the deflection coil, the magnetic field of a specific intensity and direction generated by the deflection coil will cause the landing point of the electron beam on the device to be exposed to be the reference point of the target write field.
[0043] Thus, due to the high conversion accuracy of the first DAC, the positioning accuracy of the electron beam in the entire preset writing field can be ensured, providing a precise positioning reference for subsequent exposure in the target writing field, ensuring the stitching accuracy between sub-writing fields, and thereby improving the overall exposure accuracy.
[0044] Step 013: After the electron beam is aligned with the reference point, the deflection coil is controlled by the second digital-to-analog converter to deflect the electron beam so that the deflected electron beam exposes the points corresponding to the exposure coordinates of the target writing field.
[0045] Specifically, after the electron beam is aligned with the reference point of the target writing field, the various exposure coordinates of the target writing field are converted into corresponding digital commands, taking into account the influence of the reference coordinates of the target writing field during the conversion process. Then, each digital command is sequentially input into the second DAC, which sequentially outputs corresponding analog drive signals to the deflection coils. The deflection coils then sequentially generate corresponding magnetic fields to deflect the electron beam, ensuring that the landing points of the deflected electron beam correspond sequentially to the various exposure points of the target writing field. Because the second DAC has a high conversion rate, it can control the deflection coils to deflect the electron beam at a high conversion rate while ensuring the positioning accuracy of the electron beam, thus improving exposure efficiency.
[0046] Thus, by using the first DAC to locate and jump the target writing field, and using the second DAC to scan and expose each point to be exposed within the target writing field, both exposure accuracy and exposure rate can be taken into account, effectively improving the overall exposure efficiency of the electron beam exposure machine.
[0047] In one alternative embodiment, please refer to Figure 5 Step 013 includes: Step 0131: Determine the target digital deflection parameter based on any target exposure coordinate among the coordinates of each exposure point; Step 0132: Convert the target digital deflection parameters into a target analog drive signal using a second digital-to-analog converter. Control the deflection coil to deflect the electron beam based on the target analog drive signal, so that the deflected electron beam exposes the target exposure point corresponding to the target exposure coordinates.
[0048] Specifically, using the reference point of the target writing field as the origin, the horizontal and vertical offsets of the target's coordinates relative to the origin (i.e., the reference point coordinates) are determined. Combining hardware parameters such as the magnetic field sensitivity of the deflection coil and the electron beam deflection gain, the horizontal and vertical offsets are converted into target digital deflection parameters recognizable by the second DAC.
[0049] Then, the second DAC converts the target digital deflection parameters into a continuous target analog drive signal according to the preset conversion accuracy and gain. The target analog drive signal includes current / voltage control quantities on the horizontal and vertical axes. The deflection circle generates a corresponding target magnetic field based on the current / voltage control quantities in the target analog drive signal. The electron beam is deflected under the action of the target magnetic field, and the landing point moves to the target exposure point, thus triggering the exposure action to complete the processing of a single exposure point.
[0050] By sequentially performing steps 0131, 0132, and triggering the exposure action on each point to be exposed in the target writing field, the graphic exposure of the entire target writing field can be completed.
[0051] In this way, the electron beam can be independently controlled on a single point to be exposed, ensuring the positional accuracy of point-by-point exposure, while the exposure rate can be increased based on the fast response of the second DAC.
[0052] In one alternative embodiment, please refer to Figure 6 The deflection coil control method also includes step 014, and step 0131 includes step 01311, which will be explained in detail below.
[0053] Step 014: Based on the target exposure coordinates and the reference coordinates of the target write field, determine the attribution result. The attribution result includes whether the target exposure point corresponding to the target exposure coordinates is located in the target write field. Step 01311: When the target to be exposed point is located in the target writing field, determine the target digital deflection parameters based on the target to be exposed coordinates.
[0054] Among them, the attribution result is the judgment result of whether the point to be exposed is located in the target writing field.
[0055] It is understandable that if the target point to be exposed, corresponding to the target's coordinates, is not within the target's writing field, the electron beam will be outside the deflection range of the second DAC (i.e., the nonlinear region) after being deflected. Nonlinear errors will cause a significant deviation between the actual landing point of the electron beam and the target point to be exposed, resulting in image distortion. This, in turn, increases the error of writing field stitching and reduces the overall exposure accuracy.
[0056] Therefore, it is necessary to determine the (horizontal and vertical) distance between the target exposure point and the reference point of the target write field based on the horizontal and vertical coordinates of the target exposure coordinates and the reference coordinates of the target write field, thereby determining whether the target exposure point is located within the target write field. This verifies the validity of the target exposure point and avoids image distortion caused by edge nonlinearity.
[0057] When the target point to be exposed is located in the target writing field, the process of exposing the target point to be exposed by deflecting electron beam is carried out. The specific process has been described in detail in steps 0131 and 0132, and will not be repeated here to avoid repetition.
[0058] Optionally, if the target point to be exposed is not in the target write field, a reference point located in the same sub-write field as the target point to be exposed is determined based on the target point to be exposed coordinates, and then the reference coordinates of the reference point and the corresponding sub-write field are determined. The sub-write field is updated to the target write field, and then step 012 is entered to reposition the reference point of the target write field.
[0059] In one alternative embodiment, please refer to Figure 7 Step 014 includes: Step 0141: If the difference between the horizontal coordinates of the target to be exposed coordinates and the reference coordinates of the target write field is less than 0.5 times the horizontal side length, and the difference between the vertical coordinates is less than 0.5 times the vertical side length, the assignment result is determined to be that the target to be exposed point is located in the target write field.
[0060] The target write field is a rectangle, which includes the horizontal side length and the vertical side length. The reference coordinates of the target write field correspond to the center position of the target write field (i.e., the intersection of the diagonals).
[0061] Since the reference point corresponding to the reference coordinates of the target writing field is the center of the target writing field, the distance from the reference point to the two horizontal sides of the target writing field is half the length of the vertical side, and the distance from the reference point to the two vertical sides of the target writing field is half the length of the horizontal side. The target exposure coordinates represent the position of the target exposure point in the preset writing field, and the reference coordinates represent the position of the reference point of the target writing field in the preset writing field. Therefore, the difference between the horizontal coordinates of the two (the target exposure coordinates and the reference coordinates of the target writing field) must be less than 0.5 times the length of the horizontal side, and the difference between the vertical coordinates must be less than 0.5 times the length of the vertical side, in order to determine that the target exposure point is located in the target writing field.
[0062] Optionally, if the difference between the horizontal coordinates of the target to be exposed and the reference coordinates of the target write field is greater than or equal to 0.5 times the horizontal side length, or the difference between the vertical coordinates is greater than or equal to 0.5 times the vertical side length, the assignment result is determined to be that the target to be exposed point is not in the target write field.
[0063] In this way, it is possible to accurately determine whether the target point to be exposed is located in the target field, thereby improving the overall exposure accuracy.
[0064] In one alternative embodiment, please refer to Figure 8 Step 013 includes: Step 0133: Control the deflection coil to deflect the electron beam through the second digital-to-analog converter, so that the deflected electron beam exposes each point to be exposed in the target writing field in a line-by-line scanning manner.
[0065] Specifically, line-by-line scanning refers to the process of covering the target writing field line by line with a deflected electron beam along a parallel path. After completing the scan and exposure of one line (horizontal or vertical), the process jumps to the starting position of the next line, and the points to be exposed in each line of the target writing field are exposed sequentially. The coordinates to be exposed in the target writing field are arranged in the order of line-by-line scanning; for example, coordinates to be exposed with the same horizontal coordinate are grouped together, and within each group, they are arranged in ascending or descending order of vertical coordinate. Each coordinate to be exposed is used as the target coordinate to be exposed in the sorted order and proceeds to step 0131 to expose each point to be exposed sequentially.
[0066] For example, please see Figure 9 The target writing field is the area within the rectangular solid line frame. Point S1 is the reference point of the target writing field. All the dots except point S1 are the points to be exposed in the target writing field (such as points A1-1, A1-2, etc.). Figure 9 The progressive scan method shown in the figure is as follows: starting from exposing point A1-1, it first moves horizontally to expose point A8-1, and then moves up to expose the nearest point to be exposed, A8-2; then it moves horizontally to expose point A1-2, and then moves up to expose the nearest point to be exposed, A1-3. The subsequent forward direction is basically similar, and will not be described in detail here.
[0067] For example, please see Figure 10 The target write field is the area within the rectangular solid line frame. Point S1 is the reference point of the target write field. All the dots except point S1 are the points to be exposed in the target write field (such as points A1-1, A8-1, etc.). Figure 10 The progressive scan method shown in the figure is as follows: starting with exposure to point A1-1, first move horizontally to expose to point A8-1, and then move up to the nearest row; first expose to point A1-2, then move horizontally to expose to point A8-2, and then move up to the nearest row; then expose to point A1-3, and the subsequent forward direction is basically similar, so it will not be described again here.
[0068] Optionally, starting with exposure at point A1-1, first advance vertically to point A1-8, then move right to the nearest column; first expose at point A2-1, then advance vertically to point A2-8, then move right to the nearest column; then expose at point A1-3, and the subsequent advance direction is basically similar, so it will not be described again here.
[0069] Thus, by performing exposure through line-by-line scanning, the electron beam trajectory can be ensured to be regular and orderly, avoiding repeated exposure or underexposure, and guaranteeing the integrity and uniformity of the pattern. Furthermore, it avoids drastic adjustments to the electron beam deflection direction, reducing the loss of deflection accuracy in the second DAC and improving overall exposure accuracy.
[0070] In one alternative embodiment, please refer to Figure 2 The deflection coil includes a first deflection coil and a second deflection coil. The first deflection coil is controlled by a first digital-to-analog converter (DAC), and the second deflection coil is controlled by a second DAC. The two DACs each control a corresponding set of deflection coils, achieving rapid and precise deflection of the electron beam through division of labor and cooperation, thereby improving exposure efficiency.
[0071] In one alternative embodiment, please combine Figure 2 And see Figure 11 Step 012 includes step 0121, and step 013 includes step 0134, which will be explained in detail below.
[0072] Step 0121: Adjust the deflection parameters of the first deflection coil by the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinates of any target writing field in each sub-writing field. Step 0134: Control the second deflection coil to deflect the electron beam through the second digital-to-analog converter, so that the deflected electron beam exposes the points to be exposed corresponding to the various exposure coordinates of the target writing field.
[0073] Specifically, a corresponding digital instruction is generated based on the reference coordinates of the target writing field. The first DAC generates a corresponding analog signal based on the digital instruction, and provides a corresponding current / voltage to the first deflection coil based on the analog signal, thereby adjusting the deflection parameters of the first deflection coil. The magnetic field generated by the first deflection coil according to the corresponding deflection parameters enables accurate positioning of the electron beam on the target writing field.
[0074] The second DAC generates an analog signal based on the corresponding digital instruction, which then controls the second deflection coil. The basic principle is similar to that of the first DAC, and will not be elaborated further here. The magnetic fields generated by the first and second deflection coils are superimposed, forming a total magnetic field that acts on the electron beam, ensuring that the deflected electron beam accurately falls on the corresponding exposure point.
[0075] In this way, the high-precision first DAC ensures the stitching accuracy of the sub-write fields and avoids the accumulation of system errors; the high-speed second DAC ensures high-speed exposure of the points to be exposed in each sub-write field, improving the overall exposure efficiency.
[0076] All of the above technical solutions can be combined in any way to form optional embodiments of this application, and will not be described in detail here.
[0077] Based on the method described in the above embodiments, this application also provides a control device for a deflection coil, used to execute the steps in the above-described control method for a deflection coil. Please refer to... Figure 12 , Figure 12 This is a schematic diagram of a deflection coil control device 200 provided in an embodiment of this application. The deflection coil control device 200 includes: The coordinate acquisition module 201 is used to acquire the reference coordinates of each sub-field of the preset writing field and the coordinates of each field to be exposed; The alignment adjustment module 202 is used to adjust the deflection parameters of the deflection coil through the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinate of any target writing field in each sub-writing field. After the electron beam is aligned with the reference point, the deflection exposure module 203 controls the deflection coil to deflect the electron beam through the second digital-to-analog converter, so that the deflected electron beam exposes the points to be exposed corresponding to the various exposure coordinates of the target writing field.
[0078] It should be noted that the specific details of each module unit in the above-mentioned deflection coil control device have been described in detail in the embodiments of the above-mentioned deflection coil control method, and will not be repeated here.
[0079] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.
[0080] In one optional embodiment, the deflection coil control device in this application embodiment can be implemented in hardware, such as an electron beam exposure machine or a component in the electron beam exposure machine, such as an integrated circuit or a chip; the deflection coil control device can also be implemented in software, such as as an application installed in an electron beam exposure machine.
[0081] This application embodiment also provides an electron beam exposure machine, including a first digital-to-analog converter, a second digital-to-analog converter, a deflection coil, a processor, and a memory; In this embodiment, the conversion rate of the first digital-to-analog converter is lower than that of the second digital-to-analog converter, and the conversion accuracy of the first digital-to-analog converter is higher than that of the second digital-to-analog converter. The first and second digital-to-analog converters are used to control the deflection coil. A computer program is stored in the memory. The processor executes the various processes of the above-described deflection coil control method embodiment by calling the computer program stored in the memory, and can achieve the same technical effect. To avoid repetition, it will not be described again here.
[0082] Optionally, the first digital-to-analog converter is a low-speed, high-precision DAC, and the second digital-to-analog converter is a high-speed DAC. The low-speed, high-precision DAC may include, but is not limited to, a sum-increment DAC (i.e., a Σ-Δ DAC), an R-2R resistor ladder network DAC, etc.; the high-speed DAC may include, but is not limited to, a current-driven DAC, a high-speed voltage output DAC, etc., and the embodiments of this application do not limit this.
[0083] Optionally, the deflection coil 40 may include, but is not limited to, electromagnetic deflection coils, electrostatic deflection coils, multi-pole deflection coils, etc., and the embodiments of this application do not limit this.
[0084] Optionally, the electron beam exposure machine includes a display screen. The display screen can be used to display a graphical user interface (GUI) and receive operation commands generated by the user interacting with the GUI. The display screen may include a display panel and a touch panel. The display panel can be used to display information input by the user or information provided to the user, as well as various GUIs of the electron beam exposure machine, which can be composed of graphics, text, icons, video, and any combination thereof. The touch panel can be used to collect touch operations performed by the user on or near it (such as operations performed by the user using a finger, stylus, or any suitable object or accessory on or near the touch panel), generate corresponding operation commands, and execute the corresponding program according to the operation commands.
[0085] Optionally, the touch panel may include two parts: a touch detection device and a touch controller. The touch detection device detects the user's touch location and the signal generated by the touch operation, transmitting the signal to the touch controller. The touch controller receives touch information from the touch detection device, converts it into touch point coordinates, sends it to the processor, and can receive and execute commands from the processor. The touch panel may cover the display panel. When the touch panel detects a touch operation on or near it, it transmits the information to the processor to determine the type of touch event. Subsequently, the processor provides corresponding visual output on the display panel based on the type of touch event. In this embodiment, the touch panel and display panel can be integrated into the display screen to achieve input and output functions. However, in some embodiments, the touch panel and display panel can be implemented as two independent components to achieve input and output functions.
[0086] In one alternative embodiment, please refer to Figure 13 , Figure 13 This is a schematic diagram of the electron beam exposure machine provided in an embodiment of this application. The electron beam exposure machine 300 includes a processor 301, a memory 302, a first digital-to-analog converter 310, a second digital-to-analog converter 320, and a deflection coil 330. The first digital-to-analog converter 310 and the second digital-to-analog converter 320 are used to control and drive the deflection coil 330. The memory 302 stores a computer program 303 that can run on the processor 301. When the processor 301 executes the computer program 303, it implements the various processes of the above-described embodiment of the deflection coil control method and achieves the same technical effect. To avoid repetition, it will not be described again here.
[0087] This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described deflection coil control method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.
[0088] The processor can be the processor in the electron beam lithography machine described in the above embodiments. The computer-readable storage medium can be a computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, etc.
[0089] Computer-readable media can include computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented by any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid-state storage technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape cassettes, magnetic tape, disk storage, or other magnetic storage devices. Of course, those skilled in the art will recognize that computer storage media are not limited to the above-mentioned types.
[0090] This application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the aforementioned deflection coil control method. The processor may be the processor in the electron beam exposure machine described in the above embodiments. When the computer instructions are executed by the processor, they implement various processes of the embodiments of the aforementioned deflection coil control method and achieve the same technical effects; therefore, to avoid repetition, they will not be described again here.
[0091] It is understood that in the specific implementation of this application, data related to user identity or characteristics is involved. When the above embodiments of this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.
[0092] In the description of this specification, the references to terms such as "certain embodiments," "an alternative embodiment," and "exemplarily" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0093] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.
[0094] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. A control method for a deflection coil, characterized in that, An electron beam exposure machine, comprising a first digital-to-analog converter (D / A converter), a second D / A converter, and a deflection coil, wherein the conversion rate of the first D / A converter is lower than that of the second D / A converter, and the conversion accuracy of the first D / A converter is higher than that of the second D / A converter, the method comprising: Obtain the reference coordinates of each sub-field of the preset writing field and the coordinates of each field to be exposed; The deflection parameters of the deflection coil are adjusted by the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinate of any target write field in each of the sub-write fields. After the electron beam is aligned with the reference point, the deflection coil is controlled by the second digital-to-analog converter to deflect the electron beam, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of each target writing field.
2. The control method for the deflection coil according to claim 1, characterized in that, The sub-write field is rectangular and is located within the deflection range of the second digital-to-analog converter.
3. The control method for the deflection coil according to claim 1, characterized in that, The step of controlling the deflection coil to deflect the electron beam via the second digital-to-analog converter, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of each target write field, includes: The target digital deflection parameter is determined based on any target exposure coordinate among the coordinates of each of the aforementioned exposure points; The target digital deflection parameters are converted into a target analog drive signal by the second digital-to-analog converter. Based on the target analog drive signal, the deflection coil is controlled to deflect the electron beam so that the deflected electron beam exposes the target exposure point corresponding to the target exposure coordinates.
4. The control method for the deflection coil according to claim 3, characterized in that, After the electron beam is aligned with the reference point, the method further includes: Based on the target exposure coordinates and the reference coordinates of the target write field, the attribution result is determined, and the attribution result includes whether the target exposure point corresponding to the target exposure coordinates is located in the target write field; The step of determining the target digital deflection parameter based on any target exposure coordinate among the coordinates of each of the exposure points includes: When the target exposure point is located at the target write field, the target digital deflection parameter is determined based on the target exposure coordinates.
5. The control method for the deflection coil according to claim 4, characterized in that, The target write field is rectangular, comprising a horizontal side length and a vertical side length. The reference coordinates of the target write field correspond to the center position of the target write field. Determining the attribution result based on the target to-be-exposed coordinates and the reference coordinates of the target write field includes: If the difference between the horizontal coordinates of the target to be exposed coordinates and the reference coordinates of the target write field is less than 0.5 times the horizontal side length and the difference between the vertical coordinates is less than 0.5 times the vertical side length, the attribution result is determined to be that the target to be exposed point is located in the target write field.
6. The control method for the deflection coil according to any one of claims 1-5, characterized in that, The step of controlling the deflection coil to deflect the electron beam via the second digital-to-analog converter, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of each target write field, includes: The second digital-to-analog converter controls the deflection coil to deflect the electron beam, so that the deflected electron beam exposes each point to be exposed in the target writing field in a line-by-line scanning manner.
7. The control method for the deflection coil according to claim 1, characterized in that, The deflection coil includes a first deflection coil and a second deflection coil, the first deflection coil being controlled by the first digital-to-analog converter, and the second deflection coil being controlled by the second digital-to-analog converter.
8. The control method for the deflection coil according to claim 7, characterized in that, The step of adjusting the deflection parameters of the deflection coil through the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinates of any target write field in each of the sub-write fields includes: The deflection parameters of the first deflection coil are adjusted by the first digital-to-analog converter so that the deflected electron beam is aligned with the reference point corresponding to the reference coordinate of any target write field in each of the sub-write fields. The step of controlling the deflection coil to deflect the electron beam via the second digital-to-analog converter, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of each target write field, includes: The second deflection coil is controlled by the second digital-to-analog converter to deflect the electron beam, so that the deflected electron beam exposes the points corresponding to the exposure coordinates of the target writing field.
9. An electron beam exposure machine, characterized in that, Includes a first digital-to-analog converter, a second digital-to-analog converter, a deflection coil, a processor, and a memory; The conversion rate of the first digital-to-analog converter is lower than that of the second digital-to-analog converter, and the conversion accuracy of the first digital-to-analog converter is higher than that of the second digital-to-analog converter. The first digital-to-analog converter and the second digital-to-analog converter are used to control the deflection coil. The memory stores a computer program, and the processor executes the deflection coil control method as described in any one of claims 1-8 by calling the computer program stored in the memory.
10. A computer-readable storage medium, characterized in that, The device stores a computer program that, when executed by a processor, implements the control method for the deflection coil as described in any one of claims 1-8.
11. A computer program product, characterized in that, It includes computer instructions, which, when executed by a processor, implement the control method for the deflection coil as described in any one of claims 1-8.