Ion beam current measuring device and method thereof

Abstract

The invention discloses an ion beam current measuring device and method, the device comprises a vertical scanning assembly, a horizontal scanning assembly, a beam current collecting plate and a controller, the vertical scanning assembly comprises a first beam limiting plate and two moving mechanisms, the first beam limiting plate comprises two beam limiting plates which are arranged up and down, beam limiting grooves in the two beam limiting plates are spliced to form a first beam limiting seam, and the beam collecting plate is connected with the first beam limiting seam; the horizontal scanning assembly comprises a second beam limiting plate and two moving mechanisms, the second beam limiting plate comprises the two beam limiting plates which are horizontally arranged in the left-right direction, beam limiting grooves in the two beam limiting plates are spliced to form a second beam limiting seam, and the moving mechanisms drive the two beam limiting plates to move in the left-right direction. The beam collecting plate is arranged at the downstream of the first beam limiting plate and the second beam limiting plate which are arranged front and back, and the controller adjusts the width of the two beam limiting seams and the motion scanning direction of the first beam limiting plate and the second beam limiting plate by controlling the four moving mechanisms. And beam information of each position point on the beam acquisition plate is obtained, and the beam cross section shape and the beam density distribution are determined according to the beam information.

Description

Technical Field

[0001] The present invention relates to the technical field of ion beam measurement. More specifically, the present invention relates to an ion beam current measurement device and method thereof. Background Art

[0002] With the improvement of integrated circuit process technology, higher requirements are put forward for ion implantation equipment. The requirements for the beam current intensity, beam profile, density distribution, etc. of the implanted ion beam are increasing day by day. By reasonably controlling the beam parameters, ensuring the uniformity and stability of the beam current has a great impact on the quality of the implanted products and the industrialization of ion implanters. To control the uniformity and stability of the beam current, a device for measuring various parameters and density distribution of the beam current is necessary to analyze and detect the beam current state in real time online to ensure the quality and stability of the implantation process. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention innovatively provides an ion beam current measurement device and method thereof, which has high measurement accuracy, no scanning blind area, can accurately locate the boundary of the beam cross-section, and then accurately determine the shape of the beam cross-section; and can accurately obtain the beam distribution density, and then determine the beam uniformity; the width of the beam-limiting slit can be adjusted, and then the smallest scanning unit can be determined to improve the measurement accuracy.

[0004] To achieve the above technical objectives, the first aspect of the present invention discloses an ion beam current measurement device, including a vertical scanning component, a horizontal scanning component, a beam current acquisition board and a controller, The vertical scanning component, the horizontal scanning component and the beam current acquisition board are arranged in a vacuum chamber, The vertical scanning component includes a first beam-limiting plate, a first moving mechanism and a second moving mechanism. The first beam-limiting plate includes an upper half beam-limiting plate and a lower half beam-limiting plate arranged vertically up and down perpendicular to the movement direction of the ion beam current. A first beam-limiting slot with a downward slot opening is provided at the lower edge of the upper half beam-limiting plate, and a second beam-limiting slot with an upward slot opening is provided at the upper edge of the lower half beam-limiting plate. The first beam-limiting slot and the second beam-limiting slot form a first beam-limiting slit. The first moving mechanism is connected to the upper half beam-limiting plate and is used to drive the upper half beam-limiting plate to move up and down in the vertical direction. The second moving mechanism is connected to the lower half beam-limiting plate and is used to drive the lower half beam-limiting plate to move up and down in the vertical direction to adjust the width of the first beam-limiting slit in the vertical direction and the movement scanning direction of the first beam-limiting plate, The horizontal scanning component includes a second beam limiting plate, a third moving mechanism, and a fourth moving mechanism. The second beam limiting plate includes a left half beam limiting plate and a right half beam limiting plate arranged horizontally on the left and right in a direction perpendicular to the movement direction of the ion beam. A third beam limiting groove with a notch facing right is formed on the right edge of the left half beam limiting plate, and a fourth beam limiting groove with a notch facing left is formed on the left edge of the right half beam limiting plate. The third beam limiting groove and the fourth beam limiting groove form a second beam limiting slit. The third moving mechanism is connected to the left half beam limiting plate and is used to drive the left half beam limiting plate to move horizontally to the left and right. The fourth moving mechanism is connected to the right half beam limiting plate and is used to drive the right half beam limiting plate to move horizontally to the left and right, so as to adjust the width of the second beam limiting slit in the horizontal direction and the movement scanning direction of the second beam limiting plate. The first beam limiting plate and the second beam limiting plate are arranged one in front of the other along the movement direction of the ion beam, and one of them is arranged in front of the other. The beam current collecting plate is arranged downstream of the first beam limiting plate and the second beam limiting plate along the movement direction of the ion beam, and is used to receive the ion beam passing through the first beam limiting slit and the second beam limiting slit. The controller is electrically connected to the beam current collecting plate, the first moving mechanism, the second moving mechanism, the third moving mechanism, and the fourth moving mechanism respectively, and is used to adjust the widths of the first beam limiting slit and the second beam limiting slit and the movement scanning directions of the first beam limiting plate and the second beam limiting plate by controlling the first moving mechanism, the second moving mechanism, the third moving mechanism, and the fourth moving mechanism, and is used to obtain the beam current information of each position point received by the beam current collecting plate and determine the beam cross-sectional shape and beam current density distribution according to the beam current information.

[0005] Further, it further includes an inhibiting magnet. The inhibiting magnet is arranged upstream of the beam current collecting plate and downstream of the first beam limiting plate and the second beam limiting plate, and is used to prevent the interference of secondary electrons and other ions on the measurement.

[0006] Further, the inhibiting magnet includes two inhibiting magnets arranged horizontally on the left and right, and the distance between the two inhibiting magnets is greater than the width of the ion beam in the horizontal direction.

[0007] Further, the upper half beam limiting plate, the lower half beam limiting plate, the left half beam limiting plate, the right half beam limiting plate, and the beam current collecting plate are all graphite plates.

[0008] Further, the method for the controller to determine the beam cross-sectional shape according to the beam current information is specifically: Fitting the two-dimensional coordinates of the beam current at each position point to obtain the beam cross-sectional shape.

[0009] Further, the method for the controller to determine the beam current density distribution according to the beam current information is specifically: The beam intensities at each position point are fitted to obtain an ion beam intensity distribution cloud map, and the beam density distribution is determined based on the ion beam intensity distribution cloud map.

[0010] To achieve the above technical objectives, the second aspect of the present invention discloses an ion beam measurement method using the ion beam measurement device described in the first aspect, including the following steps: Perform a scan in one of the vertical and horizontal directions: Keep one of the first beam limiting plate and the second beam limiting plate stationary, adjust the width of the beam limiting slit of this beam limiting plate to be greater than the theoretical width of the ion beam in the direction of the beam limiting slit width, and keep the center of the beam limiting slit of this beam limiting plate aligned with the theoretical center of the ion beam; determine the width of the other beam limiting slit, and this beam limiting plate gradually moves from one side of the theoretical center of the ion beam to the boundary of the ion beam cross-section in the scanning direction and then moves back step by step to the boundary of the ion beam cross-section on the other side. The beam collection plate receives the ion beam passing through the first beam limiting slit and the second beam limiting slit in real time, and the controller obtains the beam information at each position point received by the beam collection plate in real time. When the controller does not receive beam information during the scanning process, it is determined that the beam limiting slit has moved to the boundary of the ion beam cross-section; Perform a scan in the other of the vertical and horizontal directions: After the scan in one direction is completed, adjust the width of the beam limiting slit of the beam limiting plate that has completed the scan to be greater than the theoretical width of the ion beam in the direction of the beam limiting slit width, align the center of the beam limiting slit with the theoretical center of the ion beam and keep it stationary; determine the width of the beam limiting slit of the other beam limiting plate, and this beam limiting plate gradually moves from one side of the theoretical center of the ion beam to the boundary of the ion beam cross-section in the scanning direction and then moves back step by step to the boundary of the ion beam cross-section on the other side. The beam collection plate receives the ion beam passing through the first beam limiting slit and the second beam limiting slit in real time, and the controller obtains the beam information at each position point received by the beam collection plate in real time. When the controller does not receive beam information during the scanning process, it is determined that the beam limiting slit has moved to the boundary of the ion beam cross-section; The controller determines the beam cross-section shape and beam density distribution based on the beam information.

[0011] To achieve the above technical objectives, the third aspect of the present invention discloses an ion beam measurement method using the ion beam measurement device described in the first aspect, including the following steps: Determine the widths of the first beam limiting slit and the second beam limiting slit; Locate the intersection point of the first beam-limiting slit and the second beam-limiting slit at the theoretical center position of the ion beam current, determine the movement trajectory of the intersection point, and gradually expand the scanning range by controlling the movement of the first beam-limiting plate and the second beam-limiting plate so that the intersection point moves step by step from the theoretical center of the ion beam current to the surrounding until the boundary of the ion beam current cross-section is scanned. The beam current acquisition plate receives the ion beam current passing through the first beam-limiting slit and the second beam-limiting slit. During the scanning process, the controller real-time obtains the beam current information of each position point received by the beam current acquisition plate. When the controller cannot receive the beam current information during the scanning process, it is determined that the intersection point has moved to the boundary of the ion beam current cross-section; The controller determines the beam current cross-section shape and the beam current density distribution according to the beam current information.

[0012] Further, the step distance of each movement of the first beam-limiting plate is the width of the first beam-limiting slit, and the step distance of each movement of the second beam-limiting plate is the width of the second beam-limiting slit.

[0013] Further, the controller determines the beam current cross-section shape and the beam current density distribution according to the beam current information, specifically including: Fit the two-dimensional coordinates of the beam current at each position point to obtain the beam current cross-section shape; Fit the beam current intensities at each position point to obtain the beam current intensity distribution cloud map, and determine the beam current density distribution according to the beam current intensity distribution cloud map.

[0014] The beneficial effects of the present invention are: The ion beam current measurement device and method of the present invention have high measurement accuracy, no scanning blind area, can accurately locate the boundary of the beam current cross-section, and thus accurately determine the beam current cross-section shape; and can accurately obtain the beam current distribution density, and thus determine the beam current uniformity; the width of the beam-limiting slit can be adjusted, and thus the smallest scanning unit can be determined, improving the measurement accuracy. Description of the Drawings

[0015] Figure 1 It is a schematic structural diagram of the ion beam current measurement device according to an embodiment of the present invention (the moving mechanism is not shown).

[0016] Figure 2 It is a right view of the ion beam current measurement device according to an embodiment of the present invention.

[0017] Figure 3 It is a schematic structural diagram of the first beam-limiting plate according to an embodiment of the present invention.

[0018] Figure 4 It is a schematic structural diagram of the second beam-limiting plate according to an embodiment of the present invention.

[0019] In the figure, 1. First beam-limiting plate; 11. Upper half beam-limiting plate; 12. First beam-limiting groove; 13. Lower half beam-limiting plate; 14. Second beam-limiting groove; 15. First beam-limiting slit; 2. Second beam-limiting plate; 21. Left half beam-limiting plate; 22. Third beam-limiting groove; 23. Right half beam-limiting plate; 24. Fourth beam-limiting groove; 25. Second beam-limiting slit; 3. Beam current acquisition plate; 4. Suppression magnet. Detailed implementation mode

[0020] The ion beam current measurement device and method provided by the present invention will be explained and described in detail below in conjunction with the accompanying drawings of the specification.

[0021] This embodiment specifically discloses an ion beam current measurement device, as Figure 1 and 2 shown, including a vertical scanning component, a horizontal scanning component, a beam current acquisition plate 3 and a controller. The vertical scanning component, the horizontal scanning component and the beam current acquisition plate 3 are arranged in a vacuum cavity. In this embodiment, the vacuum cavity is a Faraday cavity. The vertical scanning component, the horizontal scanning component and the beam current acquisition plate 3 are all fixedly connected to the cavity wall of the vacuum cavity through a support member. The support member is preferably a flange plate, and a cooling water flow channel is provided in the flange plate. Flowing cooling water is introduced into the cooling water flow channel to make the temperature in the vacuum cavity appropriate.

[0022] As Figure 1 、 2 and shown in 3, the vertical scanning component includes a first beam-limiting plate 1, a first moving mechanism (not shown in the figure) and a second moving mechanism (not shown in the figure). The first beam-limiting plate 1 includes an upper half beam-limiting plate 11 and a lower half beam-limiting plate 13 arranged vertically up and down perpendicular to the movement direction of the ion beam current. Figure 1 In, the movement direction of the ion beam current in the figure is the direction perpendicular to the paper surface and inward. A first beam-limiting groove 12 with a downward-opening notch is provided at the lower edge of the upper half beam-limiting plate 11, and a second beam-limiting groove 14 with an upward-opening notch is provided at the upper edge of the lower half beam-limiting plate 13. Both the first beam-limiting groove 12 and the second beam-limiting groove 14 are horizontal long-strip grooves. The first beam-limiting groove 12 and the second beam-limiting groove 14 form a first beam-limiting slit 15. The first beam-limiting slit 15 is a horizontal long-strip slit. The first moving mechanism is connected to the upper half beam-limiting plate 11 and is used to drive the upper half beam-limiting plate 11 to move up and down in the vertical direction. The second moving mechanism is connected to the lower half beam-limiting plate 13 and is used to drive the lower half beam-limiting plate 13 to move up and down in the vertical direction to adjust the width of the first beam-limiting slit 15 in the vertical direction and the movement scanning direction of the first beam-limiting plate 1. Before scanning, first adjust the position of the connected half beam-limiting plate through the first moving mechanism and / or the second moving mechanism, adjust the relative position between the upper half beam-limiting plate 11 and the lower half beam-limiting plate 13, and then adjust the width of the first beam-limiting slit 15 in the vertical direction. The width of the first beam-limiting slit 15 is the vertical distance between the top wall of the first beam-limiting groove 12 and the bottom wall of the second beam-limiting groove 14, that is Figure 1 andFigure 3 After determining the width of the first beam-limiting slit 15 in , the upper half beam-limiting plate 11 and the lower half beam-limiting plate 13 can be simultaneously controlled to move in the same direction by the first moving mechanism and the second moving mechanism, so as to realize the up and down movement of the whole first beam-limiting plate 1 and achieve the vertical scanning. The length of the first beam-limiting slit 15 in the horizontal direction is greater than the length of the ion beam in the horizontal direction to avoid affecting the movement of the ion beam during vertical scanning. During the scanning process, the width of the first beam-limiting slit 15 can also be adjusted at any time according to needs. The boundary of the ion beam has a preset theoretical value, so the lengths of the ion beam in the horizontal and vertical directions have theoretical values. Therefore, the horizontal length of the first beam-limiting slit 15 can be set to be greater than the theoretical length of the ion beam in the same direction.

[0023] As Figure 1 、 2 and shown in Fig. 4, the horizontal scanning assembly includes a second beam-limiting plate 2, a third moving mechanism (not shown in the figure) and a fourth moving mechanism (not shown in the figure). The second beam-limiting plate 2 includes a left half beam-limiting plate 21 and a right half beam-limiting plate 23 arranged horizontally on the left and right perpendicular to the movement direction of the ion beam. A third beam-limiting groove 22 with a notch facing right is provided at the right edge of the left half beam-limiting plate 21, and a fourth beam-limiting groove 24 with a notch facing left is provided at the left edge of the right half beam-limiting plate 23. Both the third beam-limiting groove 22 and the fourth limiting groove 24 are vertical long-strip-shaped grooves. The third beam-limiting groove 22 and the fourth beam-limiting groove 24 are combined to form a second beam-limiting slit 25. The second beam-limiting slit 25 is a vertical long-strip-shaped slit. The third moving mechanism is connected to the left half beam-limiting plate 21 and is used to drive the left half beam-limiting plate 21 to move horizontally to the left and right. The fourth moving mechanism is connected to the right half beam-limiting plate 23 and is used to drive the right half beam-limiting plate 23 to move horizontally to the left and right, so as to adjust the width of the second beam-limiting slit 25 in the horizontal direction and the movement scanning direction of the second beam-limiting plate 2. Before scanning, first adjust the positions of the connected half beam-limiting plates through the third moving mechanism and / or the fourth moving mechanism, adjust the relative positions between the left half beam-limiting plate 21 and the right half beam-limiting plate 23, and then adjust the width of the second beam-limiting slit 25 in the horizontal direction. The width of the second beam-limiting slit 25 is the horizontal distance between the left groove wall of the third beam-limiting groove 22 and the right groove wall of the fourth beam-limiting groove 24, that is Figure 1 and Figure 4 After determining the width of the second beam-limiting slit 25 in and , the left half beam-limiting plate 21 and the right half beam-limiting plate 23 can be simultaneously controlled to move in the same direction by the third moving mechanism and the fourth moving mechanism, so as to realize the left and right movement of the whole second beam-limiting plate 2 and achieve the horizontal scanning. The length of the second beam-limiting slit 25 in the vertical direction is greater than the theoretical length of the ion beam in the vertical direction to avoid affecting the movement of the ion beam during horizontal scanning. During the scanning process, the width of the second beam-limiting slit 25 can also be adjusted at any time according to needs.

[0024] In this embodiment, the width of the first beam-limiting slit 15 is 0.5 mm - 2 mm, preferably 0.5 mm, 1 mm, 1.5 mm or 2 mm; the width of the second beam-limiting slit 25 is 0.5 mm - 2 mm, preferably 0.5 mm, 1 mm, 1.5 mm or 2 mm; the width of the beam-limiting slit can be adjusted within the above range. The widths of the first beam-limiting slit 15 and the second beam-limiting slit 25 during scanning can be the same or different, and are specifically set according to actual measurement requirements and the ion beam current situation. The width of the beam-limiting slit determines the minimum scanning unit. The smaller the minimum scanning unit, the higher the scanning accuracy.

[0025] The first beam-limiting plate 1 and the second beam-limiting plate 2 are arranged front and back along the direction of ion beam flow, with one of them in front of the other, that is, the first beam-limiting plate 1 can be arranged upstream in front of the second beam-limiting plate 2, and the ion beam first passes through the first beam-limiting slit 15 and then through the second beam-limiting slit 25; or the second beam-limiting slit 25 can be arranged upstream in front of the first beam-limiting plate 1, and the ion beam first passes through the second beam-limiting slit 25 and then through the first beam-limiting slit 15. This application does not make special limitations on the front and back positions of the first beam-limiting plate 1 and the second beam-limiting plate 2. The beam current collection plate 3 is arranged downstream of the first beam-limiting plate 1 and the second beam-limiting plate 2 along the direction of ion beam flow, and is used to receive the ion beam passing through the first beam-limiting slit 15 and the second beam-limiting slit 25, that is, the ion beam passes through the first beam-limiting slit 15 and the second beam-limiting slit 25 and then hits the beam current collection plate 3 and is received by the beam current collection plate 3. The beam current collection plate 3 collects the current signal of the ion beam.

[0026] The controller is electrically connected to the beam current collection plate 3, the first moving mechanism, the second moving mechanism, the third moving mechanism and the fourth moving mechanism respectively. The controller controls the start and stop of the first moving mechanism, the second moving mechanism, the third moving mechanism and the fourth moving mechanism respectively, and is used to adjust the widths of the first beam-limiting slit 15 and the second beam-limiting slit 25 and the movement scanning directions of the first beam-limiting plate 1 and the second beam-limiting plate 2 by controlling the first moving mechanism, the second moving mechanism, the third moving mechanism and the fourth moving mechanism. The four moving mechanisms can operate simultaneously or separately. For example, when scanning after the width of the first beam-limiting slit 15 is determined, the controller controls the first moving mechanism and the second moving mechanism to operate simultaneously to ensure that the width of the first beam-limiting slit 15 remains unchanged and can move up and down. The controller is also used to obtain the beam current information of each position point received by the beam current collection plate 3 and determine the beam cross-section shape and beam current density distribution according to the beam current information. The controller is connected to the beam current collection plate 3 through an analog-to-digital converter, obtains the beam current information data of each position point, and performs corresponding processing and analysis on the data to determine the beam cross-section shape and beam current density distribution. The methods for the controller to perform data analysis and processing all adopt existing methods.

[0027] Further, the method by which the controller determines the beam cross-sectional shape according to the beam information is specifically as follows: Fit the two-dimensional coordinates of the beam at each position point to obtain the beam cross-sectional shape. The method for establishing the two-dimensional coordinate system and the method for fitting the two-dimensional coordinates are both implemented by the software of the controller itself and are existing fitting methods in the art. Through the fitting of the two-dimensional coordinates, the deviation between the actual center and the theoretical center of the ion beam can also be determined, and then the injection position of the ion beam can be adjusted to improve the stability and accuracy of ion implantation.

[0028] Further, the method by which the controller determines the beam density distribution according to the beam information is specifically as follows: Fit the beam intensities at each position point to obtain a contour map of the ion beam intensity distribution, and determine the beam density distribution according to the contour map of the ion beam intensity distribution. The controller can directly obtain the beam intensity based on the received data, then fit to obtain the contour map of the ion beam intensity distribution, and the beam density distribution can be determined from the contour map of the ion beam intensity distribution, and then the uniformity of the ion beam can be determined.

[0029] In some embodiments, as Figure 1 and 2 shown, the ion beam measurement device of the present application further includes a suppression magnet 4. The suppression magnet 4 is arranged upstream of the beam collection plate 3 and downstream of the first beam limiting plate 1 and the second beam limiting plate 2, and is used to prevent the interference of secondary electrons and other ions on the measurement and improve the measurement accuracy.

[0030] Further, as Figure 1 shown, the suppression magnet 4 includes two suppression magnets 4 arranged left and right. The distance between the two suppression magnets 4 is greater than the width of the ion beam in the horizontal direction. Using the two suppression magnets 4 can provide a magnetic field with sufficient intensity to effectively prevent the interference of secondary electrons and other ions on the measurement.

[0031] In this embodiment, the upper beam limiting plate 11, the lower beam limiting plate 13, the left beam limiting plate 21, the right beam limiting plate 23, and the beam collection plate 3 are all graphite plates.

[0032] Optionally, the first moving mechanism, the second moving mechanism, the third moving mechanism, and the fourth moving mechanism all adopt existing moving mechanisms, such as a moving mechanism composed of a slider, a slide rail, and a motor. The slide rail is fixed in the vacuum chamber through a support member. The chute direction of the slide rail is horizontally or vertically placed. The slider is snapped into the chute of the slide rail and can slide along the chute. Limit blocks can be provided at both ends of the slide rail to limit the boundary of the slider's sliding. The body of the motor is fixedly connected to the support member in the vacuum chamber. The output shaft of the motor is connected to the slider through a transmission mechanism. The motor is electrically connected to the controller, and the controller controls the forward and reverse rotation of the motor to control the reciprocating movement of the slider along the slide rail. The transmission mechanism can be a lead screw mechanism. The chutes on the slide rails of the first moving mechanism and the second moving mechanism are vertically arranged, and the first moving mechanism is above the second moving mechanism. The chutes on the slide rails of the third moving mechanism and the fourth moving mechanism are both horizontally arranged, and the third moving mechanism is arranged on the left side of the fourth moving structure.

[0033] The present application also discloses an ion beam current measurement method using the ion beam current measurement device described in the above embodiment, including the following steps: S1. Perform scanning in one of the vertical and horizontal directions: Keep one of the first beam limiting plate 1 and the second beam limiting plate 2 stationary, adjust the width of the beam limiting slit of this beam limiting plate to be greater than the theoretical width of the ion beam current in the width direction of the beam limiting slit, keep the center of the beam limiting slit of this beam limiting plate aligned with the theoretical center of the ion beam current, the controller controls the corresponding moving mechanism to drive the two half beam limiting plates where the beam limiting slots forming the beam limiting slit are located to move and adjust their relative positions, thereby adjusting the width of the beam limiting slit; determine the width of the other beam limiting slit. Similarly, the controller controls the corresponding moving mechanism to drive the two half beam limiting plates where the beam limiting slots forming the beam limiting slit are located to move and adjust their relative positions, thereby adjusting the width of the beam limiting slit. After adjustment, keep the width of the beam limiting slit unchanged. The width of the beam limiting slit is adjusted according to actual needs. The width of this beam limiting slit is less than the theoretical width of the ion beam current center in this direction, that is, determine the smallest scanning unit. This beam limiting plate moves step by step from one side of the theoretical center of the ion beam current to the boundary of the ion beam cross-section in the scanning direction and then moves step by step in the reverse direction to the boundary of the ion beam cross-section on the other side. The step distance of each movement is the width of the beam limiting slit on this beam limiting plate. The beam current acquisition plate 3 receives the ion beam current passing through the first beam limiting slit 15 and the second beam limiting slit 25 in real time. The controller obtains the beam current information of each position point received by the beam current acquisition plate 3 in real time. When the controller does not receive beam current information during the scanning process, it is determined that the beam limiting slit has moved to the boundary of the ion beam cross-section; after the width of the beam limiting slit is adjusted, the controller synchronously controls the moving mechanisms connected to the two half beam limiting plates forming this beam limiting slit, and the two half beam limiting plates move simultaneously, thus realizing the scanning movement. The initial position of the scanning beam limiting plate can be at any position, its center can be aligned with the theoretical center of the ion beam current, or near the theoretical center of the ion beam current. First, scan in one side of the scanning direction and move in the direction away from the theoretical center of the ion beam current in this side. During the movement, the controller receives the beam current information in real time. When the controller does not receive beam current information, it indicates that the beam limiting plate has moved to the boundary of the ion beam cross-section on this side. The controller then controls the moving mechanism to control the beam limiting plate to move in the reverse direction. During the reverse movement, the beam limiting slit first passes through the theoretical center of the ion beam current and then moves to the other side. When the controller does not receive beam current information again, it indicates that the beam limiting slit has moved to the boundary of the ion beam cross-section on this side, and there is no scanning blind area in this direction.

[0034] S2. Perform scanning in the other vertical and horizontal directions: After one - direction scanning is completed, adjust the width of the collimation slit of the collimation plate that has completed scanning to be greater than the theoretical width of the ion beam current in the direction of the collimation slit width. Align the center of the collimation slit with the theoretical center of the ion beam current and keep it stationary. Specifically, the collimation plate that has just completed scanning is at the boundary of the ion beam current cross - section. First, control the moving mechanism to drive this collimation plate to move until the center of the collimation slit is aligned with the theoretical center of the ion beam current, and then adjust the width of the collimation slit to be greater than the theoretical width of the ion beam current in this direction to avoid affecting the scanning accuracy. Determine the width of the collimation slit of the other collimation plate. The width of the collimation slit is adjusted according to actual needs, and this width is less than the theoretical width of the ion beam current center in this direction, that is, determine the smallest scanning unit. This collimation plate moves step by step from one side of the theoretical center of the ion beam current to the boundary of the ion beam current cross - section in the scanning direction and then moves step by step in the reverse direction to the boundary of the ion beam current cross - section on the other side. The specific scanning method is the same as above. The beam collection plate 3 receives the ion beam current passing through the first collimation slit 15 and the second collimation slit 25 in real - time. The controller obtains the beam information of each position point received by the beam collection plate 3 in real - time. When the controller does not receive beam information during the scanning process, it is determined that the collimation slit has moved to the boundary of the ion beam current cross - section; S3. The controller determines the beam cross - section shape and beam density distribution according to the beam information.

[0035] Preferably, first perform the scanning of the collimation plate in the front. For example, if the first collimation plate 1 is in front of the second collimation plate 2, first control the first collimation plate 1 to move up and down for vertical scanning. The controller controls the third moving mechanism and the fourth moving mechanism to move the second collimation plate 2 until the center of the second collimation slit 25 is aligned with the theoretical center of the ion beam current. Then the controller controls the third moving mechanism and the fourth moving mechanism to adjust the relative positions of the left - half collimation plate 21 and the right - half collimation plate 23, thereby realizing the adjustment of the width of the second collimation slit 25, so that the width of the second collimation slit 25 is greater than the theoretical width of the ion beam current in the horizontal direction. Then, the controller controls the first moving mechanism and the second moving mechanism to adjust the relative positions of the upper - half collimation plate 11 and the lower - half collimation plate 13, realizing the adjustment of the width of the first collimation slit 15. The width of the first collimation slit 15 is less than the theoretical width of the ion beam current in the vertical direction, that is, determine the smallest scanning unit. Then, the controller controls the first moving mechanism and the second moving mechanism to work simultaneously, and the upper - half collimation plate 11 and the lower - half collimation plate 13 move simultaneously, keeping the width of the first collimation slit 15 unchanged. For example, the upper - half collimation plate 11 and the lower - half collimation plate 13 move up simultaneously until the controller does not receive beam information, then it is judged that the first collimation slit 15 has moved and scanned to the upper boundary of the ion beam current cross - section, and then control the first collimation plate 1 to move down until the controller does not receive beam information again, then it is judged that the first collimation slit 15 has moved to the lower boundary of the ion beam current cross - section, and thus the vertical - direction scanning is completed.

[0036] Then, a horizontal scan is performed. At this time, the first beam-limiting slit 15 that has just completed the vertical scan is located at the lower boundary of the ion beam cross-section. First, move the first beam-limiting plate 1 to align the center of the first beam-limiting slit 15 with the theoretical center of the ion beam. Then, adjust the width of the first beam-limiting slit 15 to be greater than the theoretical vertical width of the ion beam. Next, adjust the width of the second beam-limiting slit 25 to determine the minimum scanning unit in the horizontal direction. Then, start the horizontal scan. During the scan, the second beam-limiting plate 2 can be first controlled to move to the left. After moving to the leftmost boundary, it moves to the right. After moving to the rightmost boundary, the scan stops, thus achieving an all-round scan.

[0037] Based on the beam current information, the controller can determine the shape of the beam cross-section and the beam density distribution.

[0038] This application also discloses an ion beam current measurement method using the ion beam current measurement device described in the above embodiments, including the following steps: S1’: Determine the widths of the first beam-limiting slit 15 and the second beam-limiting slit 25. The widths of the first beam-limiting slit 15 and the second beam-limiting slit 25 are both smaller than the widths of the ion beam in the corresponding directions, that is, the minimum scanning unit is determined. S2’: Locate the intersection point of the first beam-limiting slit 15 and the second beam-limiting slit 25 at the theoretical center position of the ion beam. The shape of the intersection point is square or rectangular, and the specific shape depends on the widths of the first beam-limiting slit 15 and the second beam-limiting slit 25. If the width values are the same, the shape of the intersection point is square; if the width values are different, the shape of the intersection point is rectangular. Determine the movement trajectory of the intersection point. The controller can plan the movement trajectory of the intersection point. By controlling the movement of the first beam-limiting plate 1 and the second beam-limiting plate 2, the intersection point gradually moves from the theoretical center of the ion beam to the surrounding to gradually expand the scanning range until the boundary of the ion beam cross-section is scanned. For example, the scanning movement trajectory can be a series of square trajectories that gradually expand outward from the theoretical center of the ion beam. The scanning process is realized through the simultaneous movement of the first beam-limiting plate 1 and the second beam-limiting plate 2 and the cooperation of one moving while the other remains stationary, specifically realized by the controller's control of the moving mechanism. The beam collection plate 3 receives the ion beam current at the intersection point of the first beam-limiting slit 15 and the second beam-limiting slit 25. During the scanning process, the controller real-time obtains the beam current information of each position point received by the beam collection plate 3. When the controller cannot receive the beam current information during the scanning process, it is determined that the intersection point has moved to the boundary of the ion beam cross-section. In a specific embodiment, the scanning trajectory of the intersection point is to first move a step distance from the theoretical center of the ion beam to the surrounding for circumferential scanning, and then expand to move two step distances from the theoretical center of the ion beam for circumferential scanning, and so on.

[0039] S3’: The controller determines the shape of the beam cross-section and the beam density distribution based on the beam current information.

[0040] Further, the controller determines the beam cross-sectional shape and beam density distribution based on the beam information, specifically including: Fitting the two-dimensional coordinates of the beam at each position point to obtain the beam cross-sectional shape; the method of establishing the two-dimensional coordinate system and the fitting method of the two-dimensional coordinates are both implemented by the software of the controller itself and are existing fitting methods in the art. Through the fitting of the two-dimensional coordinates, the deviation between the actual center and the theoretical center of the ion beam can also be determined, and then the injection position of the ion beam can be adjusted to improve the stability and accuracy of ion implantation.

[0041] Fitting the beam intensities at each position point to obtain the cloud map of the ion beam intensity distribution, and determining the beam density distribution based on the cloud map of the ion beam intensity distribution. The controller can directly obtain the beam intensity according to the received data, then fit to obtain the cloud map of the ion beam intensity distribution, and the beam density distribution can be determined from the cloud map of the ion beam intensity distribution, and then the uniformity of the ion beam can be determined.

[0042] In summary, the measurement process of this application has no scanning blind area, can obtain the entire cross-section of the ion beam, can accurately locate the boundary of the beam cross-section, and then accurately determine the beam cross-sectional shape; and can accurately obtain the beam distribution density, and then determine the beam uniformity; this application determines the minimum scanning unit by adjusting the width of the beam-limiting slit, realizes the adjustability of the scanning unit, and the smaller the minimum scanning unit, the higher the scanning accuracy.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0045] In the description of this specification, the descriptions referring to terms such as "this embodiment", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any at least one embodiment or example. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0046] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0047] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and simple improvements made to the substantial content of the present invention shall be included within the protection scope of the present invention.

Claims

1. An ion beam current measuring device, characterized in that: It includes a vertical scanning component, a horizontal scanning component, a beam collection plate (3) and a controller, The vertical scanning component, the horizontal scanning component and the beam collection plate (3) are arranged in a vacuum chamber. The vertical scanning assembly comprises a first beam limiting plate (1), a first moving mechanism and a second moving mechanism. The first beam limiting plate (1) comprises an upper half beam limiting plate (11) and a lower half beam limiting plate (13) arranged vertically up and down perpendicular to the moving direction of the ion beam. The lower edge of the upper half beam limiting plate (11) is provided with a first beam limiting groove (12) with a notch facing downward, and the upper edge of the lower half beam limiting plate (13) is provided with a second beam limiting groove (14) with a notch facing upward. The first beam limiting groove (12) and the second beam limiting groove (14) are assembled into a first beam limiting slit (15). The first moving mechanism is connected to the upper half beam limiting plate (11) and is used to drive the upper half beam limiting plate (11) to move up and down in a vertical direction. The second moving mechanism is connected to the lower half beam limiting plate (13) and is used to drive the lower half beam limiting plate (13) to move up and down in a vertical direction, so as to adjust the width of the first beam limiting slit (15) in the vertical direction and the moving scanning direction of the first beam limiting plate (1). The horizontal scanning assembly comprises a second beam limiting plate (2), a third moving mechanism and a fourth moving mechanism. The second beam limiting plate (2) comprises a left half beam limiting plate (21) and a right half beam limiting plate (23) arranged horizontally left and right perpendicular to the direction of movement of the ion beam. A third beam limiting groove (22) with a notch facing right is provided on the right edge of the left half beam limiting plate (21). A fourth beam limiting groove (24) with a notch facing left is provided on the left edge of the right half beam limiting plate (23). The third beam limiting groove (22) and the fourth beam limiting groove (24) form a second beam limiting slit (25). The third moving mechanism is connected to the left half beam limiting plate (21) and is used to drive the left half beam limiting plate (21) to move left and right in a horizontal direction. The fourth moving mechanism is connected to the right half beam limiting plate (23) and is used to drive the right half beam limiting plate (23) to move left and right in a horizontal direction, so as to adjust the width of the second beam limiting slit (25) in a horizontal direction and the movement scanning direction of the second beam limiting plate (2). The first beam limiting plate (1) and the second beam limiting plate (2) are arranged front and back along the direction of movement of the ion beam, with one being arranged in front of the other; the beam collecting plate (3) is arranged downstream of the first beam limiting plate (1) and the second beam limiting plate (2) along the direction of movement of the ion beam, and is used to receive the ion beam passing through the first beam limiting slit (15) and the second beam limiting slit (25); The controller is electrically connected to the beam collection plate (3), the first moving mechanism, the second moving mechanism, the third moving mechanism and the fourth moving mechanism respectively, and is used to adjust the width of the first beam limiting slit (15) and the second beam limiting slit (25) and the movement scanning direction of the first beam limiting plate (1) and the second beam limiting plate (2) by controlling the first moving mechanism, the second moving mechanism, the third moving mechanism and the fourth moving mechanism, and is used to obtain beam information of each position point received by the beam collection plate (3) and determine the beam cross-sectional shape and beam density distribution according to the beam information.

2. The ion beam current measuring device according to claim 1, characterized in that: It also includes a suppression magnet (4), which is arranged upstream of the beam collection plate (3) and downstream of the first beam limiting plate (1) and the second beam limiting plate (2) to prevent secondary electrons and other ions from interfering with the measurement.

3. The ion beam current measuring device according to claim 2, characterized in that: The suppression magnet (4) comprises two suppression magnets (4) arranged on the left and right, and the distance between the two suppression magnets (4) is greater than the width of the ion beam in the horizontal direction.

4. The ion beam current measuring device according to claim 1, characterized in that: The upper half beam limiting plate (11), the lower half beam limiting plate (13), the left half beam limiting plate (21), the right half beam limiting plate (23) and the beam collection plate (3) are all graphite plates.

5. The ion beam current measuring device according to claim 1, characterized in that: The method for the controller to determine the beam cross-sectional shape according to the beam information is specifically: The two-dimensional coordinates of the beam at each position point are fitted to obtain the beam cross-sectional shape.

6. The ion beam current measuring device according to claim 1, characterized in that: The method for the controller to determine the beam current density distribution according to the beam current information is specifically as follows: The beam intensity at each position point is fitted to obtain an ion beam intensity distribution cloud map, and the beam density distribution is determined based on the ion beam intensity distribution cloud map.

7. An ion beam current measurement method using the ion beam current measurement device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Scan in either vertical or horizontal direction: Keep one of the first beam limiting plate (1) and the second beam limiting plate (2) stationary, adjust the width of the beam limiting slit of the beam limiting plate to be greater than the theoretical width of the ion beam in the direction of the beam limiting slit width, and keep the center of the beam limiting slit of the beam limiting plate aligned with the theoretical center of the ion beam; determine the width of the other beam limiting slit, the beam limiting plate gradually moves from one side of the theoretical center of the ion beam in the scanning direction to the boundary of the ion beam cross section, and then moves in the opposite direction to the boundary of the ion beam cross section on the other side, the beam collection plate (3) receives the ion beam passing through the first beam limiting slit (15) and the second beam limiting slit (25) in real time, the controller obtains the beam information of each position point received by the beam collection plate (3) in real time, and determines that the beam limiting slit moves to the boundary of the ion beam cross section when the controller fails to receive the beam information during the scanning process; Scan in the other direction vertically and horizontally: After scanning in one direction is completed, the beam limiting slit width of the beam limiting plate that has completed the scanning is adjusted to be greater than the theoretical width of the ion beam in the direction of the beam limiting slit width, and the center of the beam limiting slit is aligned with the theoretical center of the ion beam and remains stationary; the width of the beam limiting slit of another beam limiting plate is determined, and the beam limiting plate gradually moves from one side of the theoretical center of the ion beam in the scanning direction to the boundary of the ion beam cross section and then moves in the opposite direction to the boundary of the ion beam cross section on the other side, the beam collection plate (3) receives the ion beam passing through the first beam limiting slit (15) and the second beam limiting slit (25) in real time, the controller obtains the beam information of each position point received by the beam collection plate (3) in real time, and determines that the beam limiting slit moves to the boundary of the ion beam cross section when the controller fails to receive the beam information during the scanning process; The controller determines the beam cross-sectional shape and the beam density distribution according to the beam information.

8. An ion beam current measurement method using the ion beam current measurement device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Determining the widths of the first beam-limiting slit (15) and the second beam-limiting slit (25); The intersection of the first beam limiting slit (15) and the second beam limiting slit (25) is positioned at the theoretical center of the ion beam, the movement trajectory of the intersection is determined, and the movement of the first beam limiting plate (1) and the second beam limiting plate (2) is controlled so that the intersection gradually moves from the theoretical center of the ion beam to the periphery to gradually expand the scanning range until the boundary of the ion beam cross section is scanned, the beam collection plate (3) receives the ion beam passing through the first beam limiting slit (15) and the second beam limiting slit (25), the controller acquires beam information of each position point received by the beam collection plate (3) in real time during the scanning process, and determines that the intersection moves to the boundary of the ion beam cross section when the controller fails to receive beam information during the scanning process; The controller determines the beam cross-sectional shape and the beam density distribution according to the beam information.

9. The ion beam current measuring device according to claim 7 or 8, characterized in that: The step distance of each movement of the first beam limiting plate (1) is equal to the width of the first beam limiting slit (15), and the step distance of each movement of the second beam limiting plate (2) is equal to the width of the second beam limiting slit (25).

10. The ion beam current measuring device according to claim 7 or 8, characterized in that: The controller determines the beam cross-sectional shape and the beam density distribution according to the beam information, specifically including: Fitting the two-dimensional coordinates of the beam at each position point to obtain the beam cross-sectional shape; The beam intensity at each position point is fitted to obtain an ion beam intensity distribution cloud map, and the beam density distribution is determined based on the ion beam intensity distribution cloud map.

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