Ion implantation device and particle detection method

Abstract

An ion implantation apparatus and a particle detection method are provided to improve the detection accuracy of particles transported along with an ion beam. The ion implantation apparatus (10) comprises: a beamline device (14) for transporting an ion beam; an implantation processing chamber (16) for performing an implantation process that irradiates a wafer (W) with the ion beam; an illumination device (64) for irradiating illumination light (L) in at least one of the beamline device (14) and the implantation processing chamber (16) in a direction intersecting the transport direction of the ion beam; an imaging device (66) for capturing images of the space through which the illumination light (L) passes to generate an image; and a control device (60) for detecting particles that scatter the illumination light (L) based on the image.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2020-160485, filed on September 25, 2020. The entire contents of that Japanese application are incorporated herein by reference. Technical Field

[0002] This invention relates to an ion implantation device and a method for detecting microparticles. Background Technology

[0003] In semiconductor manufacturing processes, ion implantation is a common procedure performed to implant ions into semiconductor wafers for purposes such as altering the conductivity or crystal structure of semiconductors. In ion implantation, an ion implantation apparatus is used to deliver an ion beam along a beamline extending toward the semiconductor wafer to be implanted.

[0004] In the vacuum chamber where the ion beam is delivered, particles (contamination particles) are sometimes generated due to various factors. If these particles are delivered toward the wafer along with the ion beam, they may affect the ion implantation process into the semiconductor wafer. Therefore, an apparatus is known to irradiate a laser beam toward the beamline and measure the intensity of the scattered light based on the contamination particles to determine the flux of the contamination particles (for example, see Patent Document 1).

[0005] Patent Document 1: Japanese Patent Publication No. 2008-510295

[0006] In the vacuum chamber that carries the ion beam, luminescence sometimes occurs due to the interaction between the residual gas in the vacuum chamber and the ion beam, which can sometimes affect the detection accuracy of particles using scattered light. Summary of the Invention

[0007] One of the exemplary objectives of this invention is to provide a technique for improving the detection accuracy of microparticles transported together with an ion beam.

[0008] An ion implantation apparatus according to one aspect of the present invention comprises: a beamline device for delivering an ion beam; an implantation processing chamber for performing an implantation process in which the ion beam is irradiated onto a wafer; an illumination device for irradiating illumination light in at least one of the beamline device and the implantation processing chamber in a direction intersecting the delivery direction of the ion beam; an imaging device for generating a photographic image of the space through which the illumination light passes; and a control device for detecting particles that scatter the illumination light based on the photographic image.

[0009] Another aspect of the present invention is a particle detection method. This method includes: irradiating the space through which the illumination light passes with light in a direction intersecting the delivery direction of the ion beam; generating a photographic image of the space through which the illumination light passes; and detecting particles that scatter the illumination light based on the photographic image.

[0010] Furthermore, any combination of the above-mentioned constituent elements or the constituent elements or expressions of the present invention can be interchanged among methods, apparatuses, systems, etc., as embodiments of the present invention, and are equally effective.

[0011] Invention Effects

[0012] According to one aspect of the present invention, the detection accuracy of particles transported along with the ion beam can be improved. Attached Figure Description

[0013] Figure 1 This is a top view showing the schematic structure of the ion implantation apparatus involved in the embodiment.

[0014] Figure 2 It means Figure 1 A side view of the schematic structure of the ion implantation device.

[0015] Figure 3 This is a schematic front view illustrating an example configuration of a particle measuring apparatus targeting the vicinity of a wafer surface.

[0016] Figure 4 This is a top view schematically illustrating an example configuration of a particle measuring apparatus targeting the vicinity of a wafer surface.

[0017] Figure 5 This is a schematic front view of a modified example of a particle measuring apparatus that measures particles near the surface of a wafer.

[0018] Figure 6 This is a schematic front view of a modified example of a particle measuring apparatus that measures particles near the surface of a wafer.

[0019] Figure 7 It is a diagram that roughly illustrates the functional structure of the control device involved in the implementation method.

[0020] Figure 8 This is a diagram schematically representing the detection area of ​​the particles.

[0021] In the diagram: 10-Ion implantation device, 14-Beam line device, 16-Implantation processing chamber, 60-Control device, 62-Particle measuring device, 64-Illumination device, 66-Camera device, 70-Implantation control unit, 72-Particle analysis unit, 74-Storage unit, 76-Image analysis unit, 77-Conditions management unit, 78-Monitoring unit, 80-Camera image, 82-Candidate area, 84-Detection area, 86-Judgment range, A-Beam line, B-Ion beam, L-Illumination light, V-Field of view, W-Wafer. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the description of the drawings, the same reference numerals are used for the same elements, and repeated descriptions are omitted where appropriate. Also, the structures described below are illustrative and do not limit the scope of the present invention in any way.

[0023] Figure 1 This is a top view schematically representing the ion implantation apparatus 10 according to the embodiment. Figure 2 This is a side view showing the schematic structure of the ion implantation apparatus 10. The ion implantation apparatus 10 is configured to perform ion implantation processing on the surface of a workpiece W. The workpiece W is, for example, a substrate, or a semiconductor wafer. For ease of explanation, the workpiece W is sometimes referred to as wafer W in this specification, but this is not intended to limit the object of implantation processing to a specific object.

[0024] The ion implantation apparatus 10 is configured to reciprocate a beam in one direction, causing the wafer W to reciprocate in a direction orthogonal to the scanning direction, thereby irradiating the entire processing surface of the wafer W with the ion beam. In this specification, for ease of explanation, the direction of travel of the ion beam along the designed beamline A is defined as the z-direction, and the plane perpendicular to the z-direction is defined as the xy-plane. When scanning the workpiece W with the ion beam, the scanning direction of the beam is defined as the x-direction, and the direction perpendicular to both the z-direction and the x-direction is defined as the y-direction. Therefore, the reciprocating scanning of the beam occurs in the x-direction, and the reciprocating motion of the wafer W occurs in the y-direction.

[0025] The ion implantation apparatus 10 includes an ion generation apparatus 12, a beamline apparatus 14, an implantation processing chamber 16, and a wafer transport apparatus 18. The ion generation apparatus 12 is configured to supply an ion beam to the beamline apparatus 14. The beamline apparatus 14 is configured to transport the ion beam from the ion generation apparatus 12 to the implantation processing chamber 16. The implantation processing chamber 16 houses a wafer W to be implanted, and implantation processing is performed whereby the ion beam supplied from the beamline apparatus 14 irradiates the wafer W. The wafer transport apparatus 18 is configured to move an unprocessed wafer before implantation processing into the implantation processing chamber 16 and to remove a processed wafer after implantation processing from the implantation processing chamber 16.

[0026] The ion implantation apparatus 10 includes a vacuum exhaust system (not shown) for providing a desired vacuum environment to the ion generation apparatus 12, the beamline apparatus 14, the implantation processing chamber 16, and the wafer transport apparatus 18. By activating the vacuum exhaust system, the internal pressure (vacuum level) of at least one of the beamline apparatus 14 and the implantation processing chamber 16 changes. The internal pressure of at least one of the beamline apparatus 14 and the implantation processing chamber 16 also changes due to wafer transport based on the wafer transport apparatus 18, or the introduction of gas into the beamline apparatus 14 or the implantation processing chamber 16.

[0027] The beamline apparatus 14 includes, sequentially from the upstream side of beamline A, a mass spectrometry analysis unit 20, a beam stopping device 24, a beam shaping unit 30, a beam scanning unit 32, a beam parallelization unit 34, and an angular energy filter (AEF) 36. Furthermore, the upstream side of beamline A refers to the side closer to the ion generation device 12, and the downstream side of beamline A refers to the side closer to the injection processing chamber 16 (or beam blocker 46).

[0028] The mass spectrometry analysis unit 20 is located downstream of the ion generating apparatus 12 and is configured to select the desired ion species from the ion beam drawn from the ion generating apparatus 12 by mass spectrometry analysis. The mass spectrometry analysis unit 20 includes a mass spectrometry magnet 21, a mass spectrometry lens 22, and a mass spectrometry slit 23.

[0029] The mass spectrometer magnet 21 applies a magnetic field to the ion beam drawn from the ion generation device 12, deflecting the ion beam along different paths according to the value of the ion mass-to-charge ratio M = m / q (where m is mass and q is charge). For example, the mass spectrometer magnet 21 applies a magnetic field to the ion beam in the y-direction (in... Figure 1 and Figure 2 A magnetic field (in the -y direction) is applied to deflect the ion beam in the x direction. The magnetic field strength of the mass spectrometry analysis magnet 21 is adjusted to allow ion species with the desired mass-to-charge ratio M to pass through the mass spectrometry analysis slit 23.

[0030] The mass spectrometry lens 22 is disposed downstream of the mass spectrometry magnet 21 and is configured to adjust the focusing / diverging force of the ion beam. The mass spectrometry lens 22 adjusts the focusing position of the ion beam traveling in the z-direction through the mass spectrometry slit 23 and adjusts the mass resolution M / dM of the mass spectrometry unit 20. However, the mass spectrometry lens 22 is not a necessary component and may be omitted from the mass spectrometry unit 20.

[0031] The mass spectrometry slit 23 is located downstream of the mass spectrometry lens 22 and at a position away from the mass spectrometry lens 22. The mass spectrometry slit 23 is configured such that the beam deflection direction (x direction) caused by the mass spectrometry magnet 21 is consistent with the slit width direction, and it has an opening 23a with a shape that is relatively short in the x direction and relatively long in the y direction.

[0032] The mass spectrometry slit 23 can also be configured such that its width is variable to adjust the mass resolution. The mass spectrometry slit 23 can also be composed of two shielding elements capable of moving in the slit width direction, and configured such that the slit width can be adjusted by changing the interval between the two shielding elements. The mass spectrometry slit 23 can also be configured such that its width is variable by switching between any of a plurality of slits with different widths.

[0033] The beam-stopping device 24 is configured to temporarily deflect the ion beam from the beamline A, shielding the ion beam heading downstream towards the implantation processing chamber 16 (or wafer W). The beam-stopping device 24 can be positioned anywhere along the beamline A, for example, between the mass spectrometry lens 22 and the mass spectrometry slit 23. Since a constant distance is required between the mass spectrometry lens 22 and the mass spectrometry slit 23, by positioning the beam-stopping device 24 therebetween, the length of the beamline A can be shortened compared to positioning it at other locations, and the overall ion implantation apparatus 10 can be miniaturized.

[0034] The beam stopping device 24 includes a pair of stopping electrodes 25 (25a, 25b) and a beam collector 26. The pair of stopping electrodes 25a and 25b are positioned opposite each other across the beam line A, and are perpendicular to the beam deflection direction (x-direction) of the mass spectrometer magnet 21 in the y-direction. The beam collector 26 is located downstream of the beam line A from the stopping electrodes 25a and 25b, and is positioned away from the beam line A in the opposite direction of the stopping electrodes 25a and 25b.

[0035] The first stopping electrode 25a is positioned above the beamline A in the gravitational direction, and the second stopping electrode 25b is positioned below the beamline A in the gravitational direction. The beam collector 26 is positioned further below the beamline A in the gravitational direction and is located below the opening 23a of the mass spectrometry slit 23 in the gravitational direction. The beam collector 26 may be, for example, a portion of the mass spectrometry slit 23 before the opening 23a is formed. The beam collector 26 may also be separately constructed from the mass spectrometry slit 23.

[0036] The beam stopping device 24 deflects the ion beam and causes it to retreat from the beamline A using an electric field applied between a pair of stopping electrodes 25a and 25b. For example, by applying a negative voltage to the second stopping electrode 25b with the potential of the first stopping electrode 25a as a reference, the ion beam is deflected downwards in the gravitational direction from the beamline A and incident on the beam collector 26. Figure 2 In the diagram, the trajectory of the ion beam toward the beam collector 26 is represented by a dashed line. Furthermore, the beam stopping device 24, by setting a pair of stopping electrodes 25a and 25b to the same potential, allows the ion beam to pass downstream along the beam line A. The beam stopping device 24 is configured to operate in a first mode that allows the ion beam to pass downstream and a second mode that allows the ion beam to be incident on the beam collector 26.

[0037] A Faraday cup 28 for injecting is disposed downstream of the mass spectrometry slit 23. The Faraday cup 28 is configured to exit the incident beam A via the operation of the injector drive unit 29. The injector drive unit 29 moves the Faraday cup 28 in a direction orthogonal to the extension direction of the beam A (e.g., the y-direction). Figure 2 As shown by the dashed line, when the Faraday cup 28 of the injector is positioned on the beam line A, the ion beam directed downstream is blocked. On the other hand, as by Figure 2 As shown by the solid line, when the injector Faraday cup 28 is removed from the beam line A, the blockage of the ion beam toward the downstream side is released.

[0038] The injector Faraday cup 28 is configured to measure the beam current of the ion beam being mass-analyzed by the mass spectrometry unit 20. The injector Faraday cup 28 can measure the mass spectrometry spectrum of the ion beam by measuring the beam current while changing the magnetic field strength of the mass spectrometry magnet 21. Using the measured mass spectrometry spectrum, the mass resolution of the mass spectrometry unit 20 can be calculated.

[0039] The beam shaping unit 30 includes focusing / diverging quadrupole lenses (Q lenses) and is configured to shape the ion beam passing through the mass spectrometry analysis unit 20 into a desired cross-sectional shape. The beam shaping unit 30 is, for example, composed of an electric field-type three-segment quadrupole lens (also called a tripolar Q lens), having three quadrupole lenses 30a, 30b, and 30c. By using the three lens devices 30a to 30c, the beam shaping unit 30 can independently adjust the focusing or divergence of the ion beam in the x and y directions. The beam shaping unit 30 may include magnetic field-type lens devices, or it may include lens devices that shape the beam using both electric and magnetic fields.

[0040] The beam scanning unit 32 is configured to provide reciprocating scanning of the beam and is a beam deflection device that scans the shaped ion beam in the x-direction. The beam scanning unit 32 has a pair of scanning electrodes facing each other in the beam scanning direction (x-direction). The scanning electrode pair is connected to a variable voltage power supply (not shown), and by periodically changing the voltage applied between the scanning electrode pair, the electric field generated between the electrodes is changed, causing the ion beam to be deflected to various angles. As a result, the entire scanning range of the ion beam in the x-direction is scanned. Figure 1 In the diagram, the scanning direction and range of the beam are indicated by the arrow X, and multiple trajectories of the ion beam within the scanning range are represented by single-dot dashed lines.

[0041] The beam parallelization unit 34 is configured to make the travel direction of the scanned ion beam parallel to the designed trajectory of the beam line A. The beam parallelization unit 34 has multiple arc-shaped parallelization lens electrodes with the ion beam passing through a slit at the center in the y-direction. The parallelization lens electrodes are connected to a high-voltage power supply (not shown), so that the electric field generated by the applied voltage acts on the ion beam, aligning the travel direction of the ion beam parallel to the ground. Alternatively, the beam parallelization unit 34 can be replaced by other beam parallelization devices, such as a magnet device utilizing a magnetic field.

[0042] Downstream of the beam parallelization section 34, an AD (Accel / Decel) column (not shown) for accelerating or decelerating the ion beam may also be provided.

[0043] Angle energy filter (AEF) 36 is configured to analyze the energy of the ion beam and deflect ions of the required energy downwards and guide them to the injection processing chamber 16. The angle energy filter 36 has an AEF electrode pair for electric field deflection. The AEF electrode pair is connected to a high-voltage power supply (not shown). Figure 2 In this process, a positive voltage is applied to the upper AEF electrode and a negative voltage is applied to the lower AEF electrode, causing the ion beam to deflect downwards. Furthermore, the angular energy filter 36 can be constructed from a magnetic field deflection magnet device, or from a combination of an electric field deflection AEF electrode pair and a magnetic field deflection magnet device.

[0044] Thus, the beamline device 14 supplies the ion beam that should irradiate the wafer W to the implantation processing chamber 16.

[0045] The injection processing chamber 16, from the upstream side of beamline A, sequentially includes an energy slit 38, a plasma shower device 40, a side cup 42, a center cup 44, and a beam blocker 46. For example... Figure 2 As shown, the injection processing chamber 16 has a platform drive device 50 for holding one or more wafers W.

[0046] An energy slit 38 is located downstream of the corner energy filter 36 and, together with the corner energy filter 36, performs energy analysis of the ion beam incident on the wafer W. The energy slit 38 is an energy-defining slit (EDS) consisting of a slit with a width in the beam scanning direction (x-direction). The energy slit 38 allows an ion beam with a desired energy value or energy range to pass towards the wafer W, while shielding other ion beams.

[0047] The plasma shower device 40 is located downstream of the energy slit 38. The plasma shower device 40 supplies low-energy electrons to the ion beam and the surface (wafer processing surface) of the wafer W according to the beam current of the ion beam, and suppresses charging caused by the accumulation of positive charges on the wafer processing surface generated by ion implantation. The plasma shower device 40 includes, for example, a shower pipe through which the ion beam passes and a plasma generating device that supplies electrons into the shower pipe.

[0048] Side cups 42 (42R, 42L) are configured to measure the beam current of the ion beam during ion implantation into wafer W. For example... Figure 2As shown, the side cups 42R and 42L are offset to the left and right (in the x-direction) relative to the wafer W positioned on the beam line A, and are positioned so as not to shield the ion beam directed toward the wafer W during ion implantation. Since the ion beam scans beyond the area of ​​the wafer W in the x-direction, even during ion implantation, a portion of the scanned beam is incident on the side cups 42R and 42L. Therefore, the beam current during the ion implantation process is measured through the side cups 42R and 42L.

[0049] The center cup 44 is configured to measure the beam current on the wafer processing surface. The center cup 44 is movable in the x-direction by the action of the drive unit 45, retracting from the implantation position where the wafer W is located during ion implantation and inserting into the implantation position when the wafer W is not in the implantation position. By measuring the beam current while moving in the x-direction, the center cup 44 can measure the beam current across the entire beam scanning range in the x-direction. Alternatively, multiple Faraday cups can be arranged in an array in the x-direction to simultaneously measure the beam current at multiple positions in the beam scanning direction (x-direction).

[0050] At least one of the side cup 42 and the center cup 44 may be equipped with a single Faraday cup for measuring the beam current, or it may be equipped with an angle measuring device for measuring the angle information of the beam. The angle measuring device, for example, includes a slit and multiple current detection units disposed away from the slit in the beam travel direction (z-direction). The angle measuring device, for example, can determine the angular component of the beam in the slit width direction by measuring the beam passing through the slit using multiple current detection units arranged in the slit width direction. At least one of the side cup 42 and the center cup 44 may also be equipped with a first angle measuring device capable of measuring angle information in the x-direction and a second angle measuring device capable of measuring angle information in the y-direction.

[0051] The platform drive unit 50 includes a wafer holding device 52, a reciprocating motion mechanism 54, a torsion angle adjustment mechanism 56, and a tilt angle adjustment mechanism 58. The wafer holding device 52 includes an electrostatic chuck for holding the wafer W. The reciprocating motion mechanism 54 causes the wafer held by the wafer holding device 52 to reciprocate in the y-direction by reciprocating the wafer holding device 52 in a reciprocating motion direction (y-direction) orthogonal to the beam scanning direction (x-direction). Figure 2 In the diagram, arrow Y illustrates the reciprocating motion of wafer W.

[0052] The torsion angle adjustment mechanism 56 is a mechanism for adjusting the rotation angle of the wafer W. It adjusts the torsion angle between the alignment mark located on the outer periphery of the wafer and a reference position by rotating the wafer W about the normal to the wafer processing surface. Here, the wafer alignment mark refers to a notch or orientation plane located on the outer periphery of the wafer, which serves as a reference for the angular position of the wafer's crystal axis or circumferential direction. The torsion angle adjustment mechanism 56 is located between the wafer holding device 52 and the reciprocating motion mechanism 54, and reciprocates together with the wafer holding device 52.

[0053] The tilt angle adjustment mechanism 58 is a mechanism for adjusting the tilt of the wafer W, adjusting the tilt angle between the travel direction of the ion beam toward the wafer processing surface and the normal to the wafer processing surface. In this embodiment, the tilt angle is the angle of rotation about the x-axis of the wafer W. The tilt angle adjustment mechanism 58 is provided between the reciprocating motion mechanism 54 and the inner wall of the implantation processing chamber 16, and is configured to adjust the tilt angle of the wafer W by rotating the platform drive device 50, which includes the reciprocating motion mechanism 54, in the R direction.

[0054] The platform drive device 50 holds the wafer W so that the wafer W can move between the implantation position where the ion beam irradiates the wafer W and the transport position where the wafer W is moved in or out between the platform drive device and the wafer transport device 18. Figure 2 This indicates that the wafer W is in the injection position, and the platform drive device 50 holds the wafer W with the beam line A intersecting the wafer W. The transport position of the wafer W corresponds to the position of the wafer holding device 52 when the wafer W is moved in or out of the transport mechanism or transport robot provided on the wafer transport device 18 through the transport port 48.

[0055] A beam blocker 46 is located at the downstream end of beamline A, for example, mounted on the inner wall of the implantation chamber 16. When the wafer W is not present on beamline A, the ion beam is incident on the beam blocker 46. The beam blocker 46 is located near the transport port 48 connecting the implantation chamber 16 and the wafer transport device 18, positioned vertically below the transport port 48.

[0056] The ion implantation apparatus 10 also includes a control device 60. The control device 60 controls the overall operation of the ion implantation apparatus 10. The control device 60 is implemented in hardware by components or mechanical devices, such as a computer CPU or memory, and in software by computer programs, etc. The various functions provided by the control device 60 can be realized through the cooperation of hardware and software.

[0057] The ion implantation apparatus 10 also includes a particle measurement device 62. The particle measurement device 62 is disposed in at least one of the beamline apparatus 14 and the implantation processing chamber 16. The particle measurement device 62 is configured to measure particles passing through the beamline A or particles flying toward the wafer W. Specifically, the particle measurement device 62 is configured to measure particles in the space through which the ion beam passes, and to measure particles transported toward the wafer W together with the ion beam.

[0058] The particle measuring device 62 includes an illumination device 64 that illuminates a light source L and an imaging device 66 that captures images of the space through which the light source L passes. The illumination device 64 illuminates the light source L towards a beam line A. The imaging device 66 captures images of particles scattered by the light source L to generate an image. The control device 60 acquires the image generated by the imaging device 66 and detects particles based on the image.

[0059] In the illustrated example, the particle measuring device 62 is configured to measure particles passing through the angular energy filter 36. An illumination device 64 illuminates an illumination light L toward the space between the plurality of AEF electrodes constituting the angular energy filter 36. The illumination light L illuminates in a direction intersecting the transport direction (z-direction) of the ion beam and passes between the plurality of AEF electrodes (e.g., between the upper and lower AEF electrodes). An imaging device 66 captures an image of at least a portion of the range of the illuminated illumination light L within the space between the plurality of AEF electrodes constituting the angular energy filter 36. The field of view V of the imaging device 66 includes the space where the ion beam intersects with the illumination light L.

[0060] The illumination device 64 is configured to generate illumination light L as visible light. The illumination device 64 is configured to generate continuous illumination light L instead of pulsed illumination light, continuously illuminating the space containing the particle being measured. The illumination device 64 may also be configured to include a laser light source and generate illumination light L such as red or green laser light. The illumination device 64 may also be configured to include an LED light source and generate illumination light L that is not a laser.

[0061] The illumination device 64 is configured to generate a sheet-like illumination light L with a width in the x-direction, for example, configured to generate a laser light sheet. The illumination device 64 can also illuminate the entire scanning range of the ion beam in the x-direction with the sheet-like illumination light L. The illumination device 64 can also generate a box-like illumination light L with a width in the x-direction and a thickness in a direction orthogonal to the x-direction (e.g., the y-direction or z-direction). The illumination device 64 can be configured to switch the illumination mode of the illumination light L; for example, it can be configured to switch between sheet-like illumination light and box-like illumination light.

[0062] The illumination device 64 is configured to illuminate the beamline A from a position away from the beamline A in the y-direction (upper or lower). The illumination device 64 is positioned upstream of the angle energy filter 36, for example, between the beam parallelization section 34 and the angle energy filter 36, and is configured to illuminate the beamline A from a position higher than the beamline A, downwards. Alternatively, the illumination device 64 can also be configured to illuminate the beamline A from a position away from the beamline in the x-direction (left or right). The illumination light L illuminates at an angle relative to the beamline A, for example. The illumination light L can also illuminate orthogonally to the beamline A.

[0063] The imaging device 66 has an imaging element such as a CCD or CMOS sensor, and generates image data by capturing images of the space to be measured, which is a particle. The imaging device 66 is configured to generate a moving image by capturing multiple images at a specified frame rate (e.g., 30 or 60 frames per second). The imaging device 66 may have a wavelength filter, or it may have a bandpass filter that selectively allows the wavelength of the illumination light L to pass through. By focusing only on the wavelength of the illumination light L as the imaging target, false detection of particles caused by light different from the illumination light L can be prevented.

[0064] The imaging device 66 is configured such that its imaging direction intersects both the illumination direction of the illumination light L and the transport direction of the ion beam. The imaging direction of the imaging device 66 can intersect the plane formed by the sheet-like illumination light L obliquely or orthogonally. The imaging device 66 is configured to capture images of at least a portion of the area irradiated by the sheet-like illumination light L from a position away from the plane formed by the sheet-like illumination light L. The imaging device 66 is positioned downstream of the angle energy filter 36, for example, between the angle energy filter 36 and the energy slit 38, and is configured to have a field of view V extending downwards from a position higher than the beamline A towards the beamline A. Additionally, the illumination device 64 can also be configured to irradiate the illumination light L towards the beamline A from a position away from the angle energy filter 36 in the x-direction (left or right). The camera device 66 can also be positioned away from the angular energy filter 36 in the x direction (left or right) and configured to have a field of view V toward the beamline A in the +x direction (left to right) or -x direction (right to left).

[0065] The field of view V of the imaging device 66 includes at least a portion of the space where the ion beam and the illumination light L intersect, preferably the entire space where the ion beam and the illumination light L intersect. The field of view V of the imaging device 66 includes at least a portion of the scanning range of the ion beam in the x-direction, and may also include the entire scanning range of the ion beam in the x-direction. The field of view V of the imaging device 66 includes at least a portion of the space between the plurality of AEF electrodes of the angular energy filter 36, and may also include the entire range in the y-direction from the upper AEF electrode to the lower AEF electrode. The field of view V of the imaging device 66 may also include the space where the ion beam and the illumination light L do not intersect.

[0066] The particle measuring device 62 may also include multiple camera devices 66. These multiple camera devices 66 may be configured to capture images of the sheet-like illumination light L from different positions. The multiple camera devices 66 may be configured as a stereo camera, allowing for three-dimensional measurement of the particle's position or movement by capturing images of the sheet-like illumination light L from different positions. The multiple camera devices 66 may also be configured so that their respective fields of view V overlap. Alternatively, the multiple camera devices 66 may be configured so that their respective fields of view V do not overlap, or each camera device 66 may capture images of particles at different positions or ranges.

[0067] The configuration of the illumination device 64 and the imaging device 66 is not limited to the above configuration, and can be arbitrarily and appropriately configured according to the location or range of the space where the particles are to be measured. The particle measuring device 62 can also be configured at any location of at least one of the beam line device 14 and the injection processing chamber 16. The particle measuring device 62 can also use the vicinity of the surface of the wafer W irradiated by the ion beam in the injection processing chamber 16 as the space where the particles are to be measured. For example, the illumination device 64 can also be configured to irradiate the vicinity of the surface of the wafer W with illumination light L. The imaging device 66 can also be configured such that the field of view V of the imaging device 66 includes the range of the irradiated illumination light L near the surface of the wafer W.

[0068] Figure 3 and Figure 4 This is a schematic diagram illustrating an example configuration of a particle measuring device 62 that measures particles near the surface of wafer W. Figure 3 This is the front view when observing the surface of wafer W in the z-direction. Figure 4 This is a top view taken from above the wafer W in the -y direction. The illumination device 64 is configured such that a sheet of illumination light L illuminates the wafer W parallel to its surface. The illumination light L may not be strictly parallel to the surface of the wafer W, or it may illuminate at an angle relative to the surface of the wafer W. The illumination light L illuminates a space within a specified range (e.g., within 10 cm or 1 m) from the surface of the wafer W. The illumination device 64 illuminates the illumination light L in a manner that intersects the ion beam B incident on the wafer W. Figure 3In the diagram, the dashed box represents the implantation region C of the wafer W where the ion beam B is incident.

[0069] The illumination device 64 is mounted on the platform drive device 50 and is configured to rotate together with the wafer W as shown by arrow R via the tilt angle adjustment mechanism 58. The illumination device 64 can adjust the passing position of the illumination light L according to the tilt angle of the wafer W, so that the illumination angle of the illumination light L varies with the tilt angle of the wafer W. In the illustrated example, the illumination device 64 is positioned on the upper left side (+x and +y directions) of the wafer W. The illumination device 64 can also be positioned on the lower left side (+x and -y directions) of the wafer W. The illumination device 64 can also be positioned close to the left side (+x direction) of the wafer W, with the wafer W and the illumination device 64 aligned in the y-direction. Furthermore, when the platform drive device 50 is positioned on the right side (-x direction) of the wafer W, the illumination device 64 can also be positioned on the right side (-x direction) of the wafer W. The illumination device 64 is positioned outside the range of motion of the reciprocating motion mechanism 54. The lighting device 64 is positioned away from the wafer W and the position of the lighting device 64 in the x direction, that is, it is positioned away from directly above (+y direction side) or directly below (-y direction side) the wafer W.

[0070] The imaging device 66 is configured such that the area where the illumination light L intersects with the ion beam B is included in the field of view V. The imaging device 66 is configured such that the surface of the wafer W is not included in the field of view V of the imaging device 66. In the illustrated example, the imaging device 66 is configured to capture images of the vicinity of the surface of the wafer W from the back side (+z direction side). In the illustrated example, the imaging device 66 is configured on the upper right side (-x and +y directions side) of the wafer W. The imaging device 66 can also be configured on the lower right side (-x and -y directions side) of the wafer W. The imaging device 66 can also be configured close to the right side (-x direction side) of the wafer W, and the wafer W and the imaging device 66 can be aligned in the y direction. The imaging device 66 is configured to avoid the movable range of the reciprocating motion mechanism 54. The camera device 66 is positioned away from the wafer W and the camera device 66 being aligned in the x-direction, that is, it is positioned away from directly above (+y direction side) or directly below (-y direction side) the wafer W. By ensuring that the surface of the wafer W is not included in the field of view V, false detection of particles caused by photographing structures formed on the surface of the wafer W can be prevented.

[0071] exist Figure 3 and Figure 4 In the example shown, the camera device 66 is not mounted on the platform drive device 50, and is configured such that the field of view V does not change according to the tilt angle of the wafer W. The camera device 66 can also be configured to adjust the field of view V according to the tilt angle of the wafer W.

[0072] Figure 5 and Figure 6 This is a schematic front view illustrating a modified example of a particle measuring apparatus targeting the vicinity of a wafer surface. Figure 5 In the particle measuring device 62a shown, the camera device 66a and the illumination device 64 are similarly mounted on the platform drive device 50. Figure 6 In the particle measuring apparatus 62b shown, the camera device 66b is mounted on a drive mechanism 68 that allows the field of view V to be variable according to the tilt angle of the wafer W. The drive mechanism 68 is mounted on the inner wall of the injection processing chamber 16 and is configured to rotate as indicated by arrow Rb. The drive mechanism 68 is configured, for example, to be driven in conjunction with the rotation of the tilt angle adjustment mechanism 58 indicated by arrow R. The drive mechanism 68 can also be driven when it is necessary to measure particles near the wafer surface.

[0073] The ion implantation apparatus 10 may also include multiple particle measuring devices 62. Each of the multiple particle measuring devices 62 can also measure different positions or ranges of the beamline A. For example, a first particle measuring device can be installed in the beamline apparatus 14, and a second particle measuring device can be installed in the implantation processing chamber 16. By providing multiple particle measuring devices 62, particles at multiple positions or ranges of the beamline A can be measured. For example, by comparing the measurement results of particles at multiple positions or ranges, it is helpful to determine the particle generation source.

[0074] A portion of the particle measuring device 62 can also be located outside the vacuum chamber constituting the beam line device 14 and the injection processing chamber 16. For example, a vacuum window can be provided on the wall of the vacuum chamber, through which the illumination light L is irradiated, and the irradiation range of the illumination light L can also be photographed through the vacuum window. A replaceable cover component, such as a resin film, can be attached to the vacuum window to counteract contamination such as particle adhesion or ion beam reflection. Furthermore, it can be configured such that if the cover component is contaminated, a different cover component can be switched while maintaining the vacuum state of the apparatus. Therefore, even if the cover component is contaminated, the window component or cover component can be replaced without opening the apparatus to the atmosphere.

[0075] The particle measuring apparatus 62 may include additional optical elements such as a mirror or lens for illuminating the illumination light L, or additional optical elements such as a mirror or lens for capturing the irradiation range of the illumination light L. It may also be configured such that the position or orientation of the space containing the particles can be varied by making the position or orientation of these optical elements variable. For example, the position or orientation of the optical elements may be varied according to the tilt angle of the wafer W.

[0076] Figure 7This is a functional block diagram schematically illustrating the functional structure of the control device 60 in an embodiment. The control device 60 includes an implantation control unit 70, a particle analysis unit 72, and a storage unit 74. The implantation control unit 70 controls the operation of the ion implantation apparatus 10 according to the implantation process. The particle analysis unit 72 controls the operation of the illumination device 64 and analyzes and measures the particles in the target space based on the image generated by the imaging device 66. The storage unit 74 stores various data required for the operation of the control device 60.

[0077] The implantation control unit 70 acquires the implantation process stored in the storage unit 74 and generates an ion beam according to the implantation process. The implantation process determines a set of implantation parameters such as ion type, beam energy, beam current, beam size, wafer tilt angle, wafer twist angle, and average doping concentration. The implantation process can also determine implantation parameters for implementing non-uniform implantation. The implantation process can determine a two-dimensional doping concentration distribution for non-uniform implantation and can also determine a calibration file for variable control of the beam scanning speed or wafer movement speed.

[0078] The implantation control unit 70 adjusts the operating parameters of various devices constituting the ion implantation apparatus 10 to achieve the desired implantation parameters determined in the acquired implantation process. The implantation control unit 70 controls the ion type of the ion beam by adjusting the gas type or extraction voltage of the ion generating device 12, the magnetic field strength of the mass spectrometer 20, etc. The implantation control unit 70 controls the beam energy of the ion beam by adjusting the extraction voltage of the ion generating device 12, the applied voltage of the beam parallelization unit 34, the applied voltage of the AD column, the applied voltage of the angle energy filter 36, etc. The implantation control unit 70 controls the beam current of the ion beam by adjusting various parameters such as the gas quantity, arc current, arc voltage, source magnet current, etc., or the opening width of the mass spectrometer slit 23, etc. The implantation control unit 70 controls the beam size of the ion beam incident on the wafer processing surface by adjusting the operating parameters of the focusing / diverging device included in the beam shaping unit 30, etc. The injection control unit 70 achieves the desired wafer tilt angle and wafer torsion angle by activating the torsion angle adjustment mechanism 56 and the tilt angle adjustment mechanism 58. The injection control unit 70 controls the operation of the vacuum exhaust system to ensure that the internal pressure (vacuum) of the beamline device 14 and the injection processing chamber 16 reaches the desired value. The injection control unit 70 activates the wafer transport device 18 to control the loading and unloading of the wafer W.

[0079] The implantation control unit 70 controls the amount of dopant or the dopant distribution implanted into the wafer W during the implantation process. In the case of uneven implantation, the implantation control unit 70 variably controls the beam scanning speed and the wafer travel speed based on the acquired implantation process. The implantation control unit 70 variably controls the beam scanning speed by controlling the scanning voltage parameters commanded by the beam scanning unit 32, and variably controls the wafer travel speed by controlling the speed parameters commanded by the reciprocating motion mechanism 54. The implantation control unit 70 decreases the time change rate dV / dt of the scanning voltage to slow down the beam scanning speed in areas with relatively high dopant levels, and increases the time change rate dV / dt of the scanning voltage to speed up the beam scanning speed in areas with relatively low dopant levels. The implantation control unit 70 slows down the wafer travel speed in areas with relatively high dopant levels and speeds up the wafer travel speed in areas with relatively low dopant levels.

[0080] The particle analysis unit 72 includes an image analysis unit 76, a condition management unit 77, and a monitoring unit 78. The image analysis unit 76 detects particles based on images generated by the imaging device 66 and analyzes the amount, velocity, and size of the particles. The condition management unit 77 manages the particle analysis conditions used by the image analysis unit 76. The monitoring unit 78 monitors the particle generation status and diagnoses any abnormalities.

[0081] The image analysis unit 76 acquires image data captured by the camera device 66 and detects particles based on the brightness values ​​of each pixel in the image data. For example, the image analysis unit 76 determines that pixels with brightness values ​​exceeding a predetermined threshold contain particles, and determines that pixels with brightness values ​​below the predetermined threshold do not contain particles. The image analysis unit 76 can also detect particles based on the amount of change in brightness values ​​over time. The image analysis unit 76 can also generate a difference image by subtracting a background image that does not contain particles from the captured image generated by the camera device 66, and detect particles based on the brightness values ​​of the difference image. The background image that does not contain particles is generated, for example, based on the captured image generated by the camera device 66 and stored in the storage unit 74.

[0082] The image analysis unit 76 may also detect particles not by detecting each pixel of the captured image, but by detecting particles in each tiny region contained within the captured image. The tiny region, which serves as the detection unit for particles, is set to contain multiple pixels, for example, a 5×5 pixel area. The image analysis unit 76 divides the captured image into multiple tiny regions, sums or averages the brightness values ​​of the multiple pixels constituting the tiny region, and thereby calculates a sum or average brightness value for each tiny region. For example, if the sum or average brightness value of each tiny region exceeds a predetermined threshold, the image analysis unit 76 determines that the tiny region contains particles. Alternatively, the image analysis unit 76 may divide the difference image obtained by subtracting the background image from the captured image into multiple tiny regions, and detect particles based on the sum or average brightness value of the tiny regions in the difference image. By integrating the scattered light from the particles based on the sum or average brightness values ​​of multiple pixels, the detection accuracy of particles can be improved.

[0083] The image analysis unit 76 can also set different thresholds for particle detection for each pixel or each small region. The image analysis unit 76 can also calculate the threshold for each pixel or each small region based on multiple background images captured without containing particles. These multiple background images are captured by the imaging device 66 at different times, and their brightness values ​​fluctuate slightly over time. The image analysis unit 76 calculates the average 'a' and standard deviation 'σ' of the brightness values ​​in the multiple background images for a specific pixel or a specific small region, and uses the average 'a' and standard deviation 'σ' to determine the threshold. For example, the brightness value obtained by adding k times the average 'a' and standard deviation 'σ' can be used as the threshold 't', or it can be expressed as 't = a + kσ'. By determining the threshold 't' based on the average 'a' and standard deviation 'σ' of the brightness values ​​in multiple background images, false detection of particles caused by changes in brightness values ​​unrelated to particle generation can be prevented. The threshold 't' can be determined based on, for example, the average 'a' and standard deviation 'σ' of approximately 50 to 100 background images.

[0084] The image analysis unit 76 may also detect particles not individually for each micro-region, but when the brightness values ​​of multiple adjacent micro-regions exceed a predetermined threshold. The image analysis unit 76 designates micro-regions with brightness values ​​exceeding the predetermined threshold as "candidate regions" that may contain particles. If a predetermined number or more other candidate regions exist around a candidate region, the image analysis unit 76 determines that these candidate regions contain particles. If fewer than a predetermined number of other candidate regions exist around a candidate region, the image analysis unit 76 determines that these candidate regions do not contain particles. For example, if three or more candidate regions exist within a determination range consisting of a 5×5 set of micro-regions centered on a candidate region, the three or more candidate regions within the determination range are designated as particle detection regions. Conversely, if two or fewer candidate regions exist within a determination range consisting of a 5×5 set of micro-regions centered on a candidate region, the two or fewer candidate regions within the determination range are not designated as particle detection regions and are simply designated as candidate regions.

[0085] Figure 8 This is a schematic diagram showing the detection region 84 of the particles, illustrating an example of the distribution of the candidate region 82 and the detection region 84 determined based on the captured image 80. Figure 8 In the image, a thin solid line represents the candidate region 82, a thick solid line represents the detection region 84, and a dashed line represents the judgment range 86, which is a collection of 5×5 micro-regions. As shown, the candidate regions 82 are distributed throughout the entire captured image 80. Many candidate regions 82 exist independently, far from other candidate regions 82. Some candidate regions 82 are densely located near other candidate regions 82. The image analysis unit 76 designates the densely located candidate regions 82 as the particle detection region 84. Specifically, when there are three or more candidate regions 82 within the judgment range 86, which is a collection of 5×5 micro-regions centered on a certain candidate region 82, all three or more candidate regions 82 are designated as the detection region 84. Figure 8 In the example, 21 detection areas were detected (84).

[0086] like Figure 8As shown, by setting the dense candidate area 82 as the particle detection area 84, false detection of particles caused by changes in brightness values ​​unrelated to particle generation can be prevented. Particles generated within the beamline device 14 or the injection processing chamber 16 do not float without changing position; they typically fly with velocity. When the camera device 66 captures images of moving particles, the particle's flight path is captured, and the brightness values ​​of multiple areas corresponding to the flight path increase. Since these multiple areas corresponding to the particle's flight path are adjacent to each other, by setting the dense candidate area 82 as the detection area 84 and designating it as the particle detection target, flying particles can be detected with high precision.

[0087] The image analysis unit 76 can also infer the quantity, velocity, or size of particles based on the particle detection results. The image analysis unit 76 can also infer the quantity of particles based on the number of pixels or micro-regions where particles are detected. The image analysis unit 76 can also use the number of pixels or micro-regions where particles are detected as the number of particles. Alternatively, the number of particles can be pre-determined using a device different from the particle measuring device 62, and the correlation between the number of pixels or micro-regions where particles are detected and the number of particles can be stored in the storage unit 74. The image analysis unit 76 can also infer the number of particles based on the correlation stored in the storage unit 74. The image analysis unit 76 can also infer the number of particles that can reach the wafer W based on the correlation stored in the storage unit 74.

[0088] The image analysis unit 76 can also infer the particle velocity by analyzing the particle's motion. For example, the particle velocity can be inferred from the range of multiple detection areas 84 corresponding to the particle's flight trajectory. Alternatively, the particle velocity can be inferred by dividing the length of the connected multiple detection areas 84 by the time corresponding to the imaging cycle of the imaging device 66. The image analysis unit 76 can also infer the particle velocity by comparing multiple frames of imaged images 80 to determine the particle's flight trajectory. For example, the particle's movement can be inferred by comparing two temporally adjacent frames of imaged images 80 to determine the change in the position of the particle's detection area 84 in each frame of imaged images 80, and the inferred movement can be divided by the time corresponding to the imaging cycle of the imaging device 66 to infer the particle velocity. The image analysis unit 76 can also use multiple imaged images 80 generated by multiple imaging devices 66, such as a stereo camera, to analyze the particle's motion and infer the particle velocity.

[0089] The image analysis unit 76 can also infer the size of the particles based on the brightness value of the detection area 84 of the particles. Since the intensity of scattered light from the particles depends on the particle size (particle diameter), by pre-measuring the correlation between the particle size and the intensity of scattered light and storing this correlation in the storage unit 74, the size of the particles can be inferred from the intensity of scattered light (i.e., the brightness value). The image analysis unit 76 can also infer the size of the particles based on the electric field E acting on the particles between multiple electrodes and the acceleration α of the particles.

[0090] The condition management unit 77 stores the image generated by the imaging device 66 in the storage unit 74, and determines the particle detection conditions used by the image analysis unit 76 based on the stored image. The condition management unit 77 stores the image determined by the image analysis unit 76 to not contain particles as background images. The condition management unit 77 calculates the average value 'a' and standard deviation 'σ' of each pixel or each small region in the multiple stored background images, and determines the threshold 't' used for particle detection. The condition management unit 77 can also update the threshold 't' based on newly acquired background images. The background image can change over time as the ion implantation device 10 is used. Therefore, by updating the threshold 't' based on newly acquired background images, particles can be detected with high precision based on the difference between the background image and the background image at any point in time.

[0091] The condition management unit 77 can also change the particle detection conditions according to the operating state of the ion implantation device 10. The condition management unit 77 can also store multiple detection conditions in the storage unit 74 and change the detection conditions according to the operating state of the ion implantation device 10. The condition management unit 77 can also classify and store background images according to the operating state of the ion implantation device 10, and determine the particle detection conditions, such as the threshold t, based on multiple background images corresponding to a specific operating state. It can also switch the multiplier k of the standard deviation σ used for the threshold t according to the operating state of the ion implantation device 10.

[0092] The conditions management unit 77 can also change the detection conditions based on the beam current of the ion beam. When the beam current of the ion beam is high, the amount of light emitted in the luminescence phenomenon caused by the interaction between the residual gas in the vacuum chamber and the ion beam increases, and the brightness value of the background image, either as a whole or in part, sometimes increases. Therefore, the background image used for particle detection can also be switched according to the beam current of the ion beam. By switching the background image according to the amount of light emitted in the aforementioned luminescence phenomenon, false detection of particles caused by the luminescence phenomenon can be prevented.

[0093] The condition management unit 77 can also change the detection conditions according to the delivery state of the delivered ion beam. The condition management unit 77 can also switch the detection conditions based on whether the ion beam is in a non-scanning state where it is not being scanned by the beam scanning unit 32 or in a scanning state where it is being scanned by the beam scanning unit 32. The condition management unit 77 can also switch the detection conditions based on whether the ion beam is shielded by the beam stopping device 24 or the implanter Faraday cup 28 midway. Since the influence range of the aforementioned luminescence phenomenon varies depending on the delivery state of the ion beam, switching the background image according to the delivery state of the ion beam can prevent false detection of particles caused by the luminescence phenomenon.

[0094] The conditions management unit 77 can also change the detection conditions based on changes in the internal pressure of at least one of the beamline device 14 and the injection processing chamber 16. When the vacuum exhaust system is activated, gas is introduced into the device, or the wafer W is transported, a gas flow may sometimes be generated within the beamline device 14 or the injection processing chamber 16, causing particles to scatter along the gas flow, or increasing the amount of particle scattering. Furthermore, by introducing gas into the beamline device 14 or the injection processing chamber 16, the amount of luminescence caused by the interaction between the introduced gas and the ion beam may sometimes change. By switching the detection conditions according to such pressure changes, particles can be detected more appropriately.

[0095] The condition management unit 77 can also change the detection conditions according to the magnitude of the electric field applied to the ion beam. For example, the detection conditions can be switched according to the voltage values ​​of multiple electrodes applied to the AD column, beam parallelization section 34, angular energy filter 36, etc. When the electric field applied to the ion beam is large, particles may be accelerated by the electric field or scattered due to discharges generated between the electrodes, affecting the movement of the particles. By switching the detection conditions according to the voltage values ​​applied to multiple electrodes, particles can be detected more appropriately.

[0096] The conditions management unit 77 can also change the particle detection conditions by switching the operation of the illumination device 64. The conditions management unit 77 can also illuminate the illumination device 64 with a sheet-like illumination light L when the actual amount of particles measured is high or when the operation is expected to increase the amount of particles. By using the sheet-like illumination light L to limit the illumination range, the number of pixels or small areas that become high-brightness pixels in the image can be limited, allowing for more appropriate particle detection. The conditions management unit 77 can also illuminate the illumination device 64 with a box-shaped illumination light L when the actual amount of particles measured is low or when the operation is expected to decrease the amount of particles. By using the box-shaped illumination light L to expand the illumination range, a wider area can be measured, allowing for more appropriate particle detection.

[0097] The monitoring unit 78 stores the particle generation status, such as presence, quantity, velocity, and size, analyzed by the image analysis unit 76, in the storage unit 74. It monitors the temporal changes in particle generation status to diagnose any abnormalities in the ion implantation device 10. For example, if the quantity of particles suddenly increases, the monitoring unit 78 may consider this an abnormality and halt the implantation process or issue an alarm. The monitoring unit 78 may also prompt the user to perform maintenance on the ion implantation device 10 if the quantity of particles monotonically increases over time and exceeds a predetermined threshold. The monitoring unit 78 can also diagnose whether the environment is suitable for performing implantation processing based on the particle generation status analyzed after maintenance of the ion implantation device 10. Based on the diagnostic results, the monitoring unit 78 may also prompt the user to perform cleaning of the beamline of the ion implantation device 10.

[0098] The monitoring unit 78 can also diagnose the particle generation status for each implantation step. The monitoring unit 78 can also store the particle generation status in the storage unit 74 for each implantation step, and set a threshold for considering an abnormality in the state of the ion implantation device 10 separately for each implantation step. The monitoring unit 78 can also diagnose the particle generation status at any given time by using past particle generation statuses from the same implantation step as a reference when performing an implantation process according to a specific implantation step.

[0099] The monitoring unit 78 can also analyze the generation status of particles stored in the storage unit 74 for each injection step, and extract injection conditions that are prone to particle generation. For example, as injection conditions that are prone to particle generation, injection conditions such as ion type, beam energy, beam current, beam size, and electrode voltage can also be extracted and displayed. Furthermore, when injection conditions or injection steps that are prone to particle generation are determined, an alarm can be output when an injection process using the determined injection conditions or injection steps is to be performed.

[0100] The monitoring unit 78 can also infer the particle generation source based on the particle movement analyzed by the image analysis unit 76. For example, if there is a large number of particles traveling in a specific direction, it can be inferred that a particle generation source exists upstream of the particle's direction of travel. When multiple particle measuring devices 62 are provided at different positions corresponding to beam line A, the monitoring unit 78 can also infer the particle generation source based on the particle generation status at each position. For example, if the amount of particles upstream of beam line A increases, and the amount of particles downstream of beam line A also increases, it can be inferred that a particle generation source exists upstream of beam line A.

[0101] The present invention has been described above with reference to the various embodiments described above, but the present invention is not limited to the embodiments described above. Appropriate combinations or substitutions of the structures of the embodiments are also included in the present invention. Furthermore, based on the knowledge of those skilled in the art, it is possible to appropriately rearrange the order of combinations or processes in the various embodiments or to add various design changes or modifications to the embodiments. Embodiments with such modifications are also included within the scope of the present invention.

Claims

1. An ion implantation device, characterized in that, have: Beamline device, used to deliver an ion beam; In the implantation processing chamber, the ion beam is used to implant the wafer. An illumination device, in at least one of the beamline device and the injection processing chamber, illuminates light in a direction intersecting the delivery direction of the ion beam; A camera device that generates a camera image by capturing the space through which the illumination light passes; and The control device detects particles that scatter the illumination light based on the camera image. The illumination light is directed in a sheet-like or box-like manner, intersecting with the ion beam. The field of view of the camera device includes the entire space where the ion beam intersects with the illumination light.

2. The ion implantation apparatus according to claim 1, characterized in that, The control device changes the detection conditions of the particles according to the operating state of the beamline device.

3. The ion implantation apparatus according to claim 1 or 2, characterized in that, The control device changes the detection conditions of the particles according to the beam current of the ion beam.

4. The ion implantation apparatus according to claim 1, characterized in that, The control device changes the detection conditions of the particles according to the delivery state of the ion beam in the beamline device.

5. The ion implantation apparatus according to claim 1, characterized in that, The control device changes the detection conditions of the particles based on changes in the internal pressure of at least one of the beamline device and the injection processing chamber.

6. The ion implantation apparatus according to claim 1, characterized in that, The beamline device includes multiple electrodes for applying an electric field to the ion beam. The illumination light shines through the space between the plurality of electrodes. The camera device captures images of the space between the plurality of electrodes.

7. The ion implantation apparatus according to claim 6, characterized in that, The control device changes the detection conditions of the particles according to the voltage values ​​applied to the plurality of electrodes.

8. The ion implantation apparatus according to claim 1, characterized in that, The illumination light shines towards the vicinity of the surface of the wafer. The camera device is configured such that the surface of the wafer is not included in the field of view of the camera device.

9. The ion implantation apparatus according to claim 1, characterized in that, The implantation processing chamber is equipped with a tilt angle adjustment mechanism for adjusting the tilt angle of the wafer relative to the transport direction of the ion beam. The lighting device is configured to adjust the position of the illumination light according to the tilt angle of the wafer. The camera device is configured to adjust its field of view according to the tilt angle of the wafer.

10. The ion implantation apparatus according to claim 1, characterized in that, It is equipped with a beam deflection device that enables the ion beam to reciprocate in one direction. The field of view of the camera device includes the entire space where the scanning range of the ion beam based on the beam deflection device intersects with the illumination light.

11. The ion implantation apparatus according to claim 1, characterized in that, The illumination light shines continuously over time, and the camera device generates multiple camera images taken at different points in time.

12. The ion implantation apparatus according to claim 1, characterized in that, The control device divides the camera image into multiple micro-regions, calculates the brightness value of each micro-region by summing or averaging the brightness values ​​of the multiple pixels contained in each micro-region, and detects the presence or absence of the microparticles in each micro-region based on the brightness value of the micro-region.

13. The ion implantation apparatus according to claim 12, characterized in that, The control device identifies tiny regions with brightness values ​​exceeding a threshold, and detects the presence or absence of particles in each of the identified tiny regions based on their distribution in the captured image.

14. The ion implantation apparatus according to claim 12, characterized in that, The control device uses detection conditions for the particles determined for each of the micro-regions to detect the presence or absence of the particles in each of the micro-regions.

15. The ion implantation apparatus according to claim 14, characterized in that, The control device determines the detection conditions for the microparticles for each micro-region based on the average and standard deviation of the brightness values ​​of the micro-regions in multiple video images captured by the camera device at different time points.

16. The ion implantation apparatus according to claim 12, characterized in that, The control device infers the amount of particles present in the space captured by the camera device based on the detection results of the presence or absence of particles in each of the micro-regions.

17. The ion implantation apparatus according to claim 1, characterized in that, The control device determines the particle detection conditions to be used when the beamline device is in the specific operating state based on multiple video images captured by the camera device at different time points when the beamline device is in the specific operating state.

18. The ion implantation apparatus according to claim 1, characterized in that, The control device determines whether the image contains the particles, and updates the particle detection conditions based on the image that is determined not to contain the particles.

19. The ion implantation apparatus according to claim 1, characterized in that, The control device analyzes the movement of the particles based on the camera image and infers the size of the particles based on the analysis results of the particle movement.

Images