Electrostatic lens for reducing the de-focusing distance

Abstract

The embodiment of the application provides an electrostatic lens for reducing a defocus distance, a multi-beam charged particle system with the electrostatic lens, and relates to the technical field of electron optics. The electrostatic lens comprises a first lens through which a first charged particle beam passes and a second lens through which a second charged particle beam passes, the first lens and the second lens both comprise a first electrode layer and a second electrode layer which are stacked and insulated, in addition, the first electrode layer of the first lens protrudes outward of the electrostatic lens relative to the first electrode layer of the second lens, so that if the electrostatic lens is applied in a multi-beam charged particle system, for example, in an electron beam exposure machine, by setting the protruding structure, the defocus distance of the first charged particle beam and the second charged particle beam can be reduced, and then the focusing plane of the multi-beam charged particle system can be a plane, so that the drawing efficiency of the electron beam exposure machine is improved.

Description

Technical Field

[0001] This application relates to the field of electro-optics technology, and in particular to an electrostatic lens for reducing defocus distance, a multi-beam charged particle inspection system having the electrostatic lens, and a multi-beam charged particle mapping system having the electrostatic lens. Background Technology

[0002] Multi-beam charged particle systems are commonly used in applications such as microscopic imaging, electron microscopy, semiconductor process defect detection and mask inspection, and electron beam lithography. Because multi-beam charged particle systems use charged particles, such as electrons, which have wavelengths much smaller than ultraviolet photons, they can provide superior resolution compared to optical systems composed of glass or plastic lenses.

[0003] Figure 1 The diagram illustrates the structure of a conventional multi-beam charged particle system. This system primarily comprises a particle source 1, a collimator 2, a beam splitter 3-1, a first focusing mirror 4, and a second focusing mirror 5. The collimator 2, beam splitter 3-1, first focusing mirror 4, and second focusing mirror 5 are arranged sequentially along the beam path of the charged particle beam generated by the particle source 1. The particle source 1 is a single charged-particle source, meaning it generates a single charged particle beam. The collimator 2 expands and collimates the charged particle beam generated by the particle source 1. The expanded and collimated charged particle beam is then split into multiple charged particle beams by the beam splitter 3-1. Each charged particle beam is then focused by the first focusing mirror 4 and the second focusing mirror 5 for imaging.

[0004] Figure 2 The diagram illustrates the virtual sources obtained by extending each charged particle beam in the reverse direction after it has been expanded and collimated by collimator 2 and then split by beam splitter 3-1. For example... Figure 2 Virtual source 1 and virtual source 2 generate a distance T along the emission direction of the charged particle beam to form a field curvature, thus resulting in... Figure 2 The phenomenon shown is that the virtual source positions of each charged particle beam are different, thus, as... Figure 3 As shown, the focusing surface after passing through the first focusing lens 4 and the second focusing lens 5 is a curved surface, which will seriously reduce the resolution of the image.

[0005] How to reduce the defocus distance and flatten the focusing surface, that is, make the focusing surface a plane, in order to improve the imaging resolution is a thorny problem currently facing this field. Summary of the Invention

[0006] The embodiments of this application provide an electrostatic lens, a multi-beam charged particle inspection system having the electrostatic lens, and a multi-beam charged particle mapping system having the electrostatic lens. The main purpose is to provide an electrostatic lens that can correct field curvature, reduce defocus distance, and flatten the focusing surface of a multi-beam charged particle system.

[0007] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0008] In a first aspect, this application provides an electrostatic lens, comprising: a first electrode layer and a second electrode layer, the first electrode layer and the second electrode layer being stacked and insulated from each other; the first electrode layer comprising a first portion and a second portion, the second electrode layer comprising a first portion and a second portion, the first portion and the first portion being arranged along a stacking direction, the second portion and the second portion being arranged along a stacking direction; the first portion protruding from the second portion of the first electrode layer in a direction away from the second electrode layer; a first hole penetrating the first electrode layer along the stacking direction being formed in the first portion of the first electrode layer, and a second hole penetrating the first electrode layer along the stacking direction being formed in the second portion of the first electrode layer; a third hole communicating with the first hole being formed in the first portion of the second electrode layer, and a fourth hole communicating with the second hole being formed in the second portion of the second electrode layer.

[0009] In the electrostatic lens provided in this application embodiment, a first electrode layer has a first hole and a second hole formed therein, and a second electrode layer has a third hole and a fourth hole formed therein. The first hole and the second hole are connected, and the third hole and the fourth hole are connected. A first portion of the first electrode layer carrying the first hole and a first portion of the second electrode layer carrying the third hole can constitute a first lens, and a second portion of the first electrode layer carrying the second hole and a second portion of the second electrode layer carrying the fourth hole can constitute a second lens. In this way, when different voltages are applied to the first electrode layer and the second electrode layer, a charged particle beam can pass through the connected first hole and the third hole to converge, and another charged particle beam can pass through the connected second hole and the fourth hole to converge, thereby forming a multi-charged-particle-beam and multi-optical-column system.

[0010] If this electrostatic lens is applied to a multi-beam charged particle system, such as an electron beam lithography machine, and the first electrode layer is oriented towards the particle source in the multi-beam charged particle system, according to the Gaussian imaging theorem... In the formula Focal length For object distance, Let be the image distance, and let the focal lengths of the first and second lenses be... When they are equal, since the first portion of the first electrode layer of this application protrudes away from the second portion of the first electrode layer relative to the second portion of the first electrode layer, it can be understood that the first portion of the first electrode layer is closer to the particle source than the second portion of the first electrode layer. In this way, compared with the prior art, the object distance of the first lens is changed. and the object distance of the second lens This allows the image distance V of the first lens to be changed. The image distance V of the first lens Therefore, the distance between the focal point of the charged particle beam passing through the first and third holes and the particle source is not equal to the distance between the focal point of the charged particle beam passing through the second and fourth holes and the particle source. In this way, the electrostatic lens can correct and compensate for the field curvature, thereby achieving the purpose of flattening the focal plane formed by the multi-beam charged particle system. It can be understood that if the electrostatic lens is applied in an electron beam exposure machine, the charged particle beams passing through the electrostatic lens can be focused onto the wafer that needs to be exposed.

[0011] In one possible implementation of the first aspect, the first portion of the second electrode layer protrudes toward the direction closer to the first electrode layer relative to the second portion of the second electrode layer.

[0012] When this electrostatic lens is applied to a multi-beam charged particle system, in the first electrode layer, the first part of the first electrode layer is closer to the particle source than the second part of the first electrode layer, and in the second electrode layer, the first part of the second electrode layer is closer to the particle source than the second part of the second electrode layer. In this way, the spacing between the first part of the first electrode layer and the first part of the second electrode layer can be designed to be equal or unequal to the spacing between the second part of the first electrode layer and the second part of the second electrode layer.

[0013] In one possible implementation of the first aspect, the first portion of the second electrode layer protrudes toward the first electrode layer relative to the second portion of the second electrode layer; and along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

[0014] In this way, when a first voltage is applied to the first electrode layer, and a second voltage different from the first voltage is applied to the second electrode layer, the electric field distribution around the connected first and third holes is basically the same as the electric field distribution around the connected second and fourth holes, based on the relationship between focusing distance and electric field strength. ,as well as In the formula To focus on distance, It is a constant. The kinetic energy of the charged particle beam as it passes through the aperture (in the same multi-beam charged particle system), (for a fixed value) The voltage difference applied between the two electrode layers. This refers to the distance between the two electrode layers. In this embodiment, since d1 = d2, the first lens... and the second lens Since they are basically equal, from the perspective of electric field strength, the field curvature correction is basically the same. In addition, when the electric field strength is basically the same, the imaging effect is basically the same.

[0015] In this embodiment, the field curvature is corrected by adjusting the object distance while ensuring that the field strength distribution is basically the same.

[0016] In addition, from a manufacturing process perspective, the same manufacturing process can be used to produce the first electrode layer and the second electrode layer with the same structure, which would simplify the manufacturing process of the electrostatic lens.

[0017] In one possible implementation of the first aspect, the electrostatic lens further includes a third electrode layer stacked on the side of the second electrode layer away from the first electrode layer. The third electrode layer includes a first part and a second part. A fifth hole connected to the third hole is formed on the first part of the third electrode layer, and a sixth hole connected to the fourth hole is formed on the second part of the third electrode layer. The first part of the third electrode layer protrudes towards the second electrode layer relative to the second part of the third electrode layer. Along the stacking direction, the distance between the port of the third hole near the fifth hole and the port of the fifth hole near the third hole is d3, and the distance between the port of the fourth hole near the sixth hole and the port of the sixth hole near the fourth hole is d4, where d1=d2 and d3=d4.

[0018] In one possible implementation of the first aspect, the first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

[0019] Alternatively, when this electrostatic lens is applied to a multi-beam charged particle system, and the first electrode layer is oriented towards the particle source in the system, the first part of the first electrode layer is closer to the particle source than the second part, and the first part of the second electrode layer is farther from the particle source than the second part. Consequently, the distance between the first and second electrode layers is greater than the distance between the second and third electrode layers. That is, the distance between the first and third holes is greater than the distance between the second and fourth holes. Therefore, the electric field distribution around the connected first and third holes is different from that around the connected second and fourth holes, based on the relationship... ,as well as The first lens and the second lens They are not equal, therefore, the first lens's and the second lens Since they are not equal, this embodiment adjusts the field curvature by changing the spacing between the electrode layers.

[0020] In one possible implementation of the first aspect, the first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

[0021] Because the first portion of the first electrode layer protrudes away from the second portion of the first electrode layer relative to the second portion of the first electrode layer, even if the first portion of the second electrode layer and the second portion of the second electrode layer are in the same plane, the distance between the first portion of the first electrode layer and the first portion of the second electrode layer is greater than the distance between the second portions of the first electrode layer and the second portion of the second electrode layer. Therefore, the first lens... and the second lens Not equal, further, the first lens and the second lens Since they are not equal, this embodiment adjusts the field curvature by changing the spacing between the electrode layers.

[0022] In one possible implementation of the first aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0023] This can be understood as follows: when the apertures of the first and second holes are not equal, the larger the aperture, the smaller the difference in field strength on both sides of the hole, the weaker the ability to converge the charged particle beam, and the farther the focal point.

[0024] When the aperture of the first hole is not equal to that of the second hole in the following embodiments, for example, when field curvature correction is performed by adjusting the spacing between the first electrode layer and the second electrode layer (i.e., adjusting the field strength distribution), a large spacing may occur between the first part of the first electrode layer and the first part of the second electrode layer, which will make the size of the entire electrostatic lens very large. In this case, the field curvature can be adjusted by changing the aperture and by adjusting the field strength distribution.

[0025] In one possible implementation of the first aspect, the diameter of the first hole is equal to the diameter of the third hole; and / or, the diameter of the second hole is equal to the diameter of the fourth hole.

[0026] In one possible implementation of the first aspect, either a portion of the first electrode layer and a portion of the second electrode layer are planar structures perpendicular to the stacking direction, and the junction of the first electrode layer and the second electrode layer has a step.

[0027] This can be understood as follows: the first part of the first electrode layer where the first hole is located and the second part of the first electrode layer where the second hole is located are planar structures perpendicular to the stacking direction. If the first part of the first electrode layer that carries the first hole and the second part of the first electrode layer that carries the second hole are not planar structures, the electric field around the first hole will be asymmetrical. In addition, the electric field around the second hole will also be asymmetrical. When charged particles pass through holes with asymmetrical electric fields, their trajectories will be deflected, thus failing to achieve the preset focusing effect.

[0028] In one possible implementation of the first aspect, the electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer; and the second power terminal is electrically connected to the second electrode layer.

[0029] In this way, when a voltage is applied to the first electrode layer, the voltage of the first part of the first electrode layer and the voltage of the second part of the first electrode layer are equal. Similarly, when a voltage is applied to the second electrode layer, the voltage of the first part of the second electrode layer and the voltage of the second part of the second electrode layer are equal. Compared with setting a power terminal for each part, the embodiment given in this application is more convenient for control.

[0030] In one possible implementation of the first aspect, the electrostatic lens further includes a dielectric layer, wherein the first electrode layer, the dielectric layer, and the second electrode layer are stacked sequentially along the stacking direction; the dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole.

[0031] In other words, insulation between the first electrode layer and the second electrode layer is achieved by embedding a dielectric layer.

[0032] Secondly, this application provides a multi-beam charged particle system, wherein the electrostatic lens includes a particle source and an electrostatic lens provided in any implementation of the first aspect above, and the electrostatic lens is arranged in the beam path of the charged particles.

[0033] The multi-beam charged particle system provided in this application includes the electrostatic lens of the first aspect embodiment. Therefore, the multi-beam charged particle system provided in this application and the electrostatic lens of the above-mentioned technical solution can solve the same technical problem and achieve the same expected effect, which will not be repeated here.

[0034] In a possible implementation of the second aspect, the multi-beam charged particle system is a multi-beam charged particle inspection system, such as a scanning electron microscope. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes: a stage for mounting the object to be inspected, and a detector, wherein the multi-beam charged particles after passing through the electrostatic lens are focused on the object to be inspected; the detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

[0035] For example, when the aforementioned electrostatic lens is used in a scanning electron microscope, the charged particle beams focused by the electrostatic lens converge onto the object to be inspected mounted on the stage, such as the wafer to be inspected. Compared with existing multi-beam charged particle systems, this can more comprehensively and quickly detect defects on the object to be inspected.

[0036] In a possible implementation of the second aspect, the multi-beam charged particle system is a multi-beam charged particle patterning system, such as an electron beam exposure machine. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes a stage for mounting the object to be patterned. The multi-beam charged particles after passing through the electrostatic lens are focused on the object to be patterned, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be patterned.

[0037] For example, if the electrostatic lens mentioned above is used in an electron beam exposure machine, the charged particle beams focused by the electrostatic lens will all converge on the object to be etched on the stage. Compared with the existing multi-beam charged particle system, this can improve the etching efficiency and shorten the etching time.

[0038] Thirdly, this application provides a method for inspecting a substrate using multi-beam charged particles. The method includes: generating charged particles using a particle source; focusing the multi-beam charged particles onto the substrate using an electrostatic lens disposed in the beam path of the charged particles; and detecting secondary charged particles generated from the substrate by the multi-beam charged particles to generate a signal corresponding to the secondary charged particles. The electrostatic lens used here can be the electrostatic lens provided in any embodiment of the first aspect.

[0039] The method for multi-beam charged particle inspection of a substrate provided in this application includes the electrostatic lens of the first aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above technical solution can solve the same technical problem and achieve the same expected effect, and will not be described again here.

[0040] In a possible implementation of the third aspect, when the electrostatic lens further includes a first power terminal electrically connected to the first electrode layer and a second power terminal electrically connected to the second electrode layer, focusing multiple bundles of charged particles onto the substrate using the electrostatic lens arranged in the beam path of the charged particles further includes: applying a first voltage to the first electrode layer through the first power terminal; and applying a second voltage, which is not equal to the first voltage, to the second electrode layer through the second power terminal.

[0041] In other words, voltage can be applied simultaneously to the first electrode layer and the second electrode layer of the first lens, the second lens, and other lenses in an electrostatic lens.

[0042] In a possible implementation of the third aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0043] In this case, the electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0044] In a possible implementation of the third aspect, the first part of the second electrode layer protrudes towards the first electrode layer relative to the second part of the second electrode layer. Along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, and the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

[0045] The electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is the same as the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0046] In a possible implementation of the third aspect, the first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

[0047] Thus, the electric field distribution when the first charged particle beam in the multi-splitter passes through the connected first and third holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the connected second and fourth holes.

[0048] In a possible implementation of the third aspect, the first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

[0049] Similarly, the electric field distribution when the first charged particle beam in a multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in a multi-splitter passes through the second and fourth interconnected holes.

[0050] Fourthly, this application provides a method for etching on an object coated with an anti-corrosion agent, the method comprising: generating charged particles using a particle source; and focusing multiple beams of charged particles onto the object to be etched using an electrostatic lens disposed in the beam path of the charged particles, thereby forming a particle beam spot on the object to be etched. The electrostatic lens here may be the electrostatic lens provided in any embodiment of the first aspect.

[0051] The method for engraving on an object coated with an anti-corrosion agent provided in this application includes the electrostatic lens of the first aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above technical solution can solve the same technical problem and achieve the same expected effect, and will not be described again here.

[0052] In a possible implementation of the fourth aspect, when the electrostatic lens further includes a first power terminal electrically connected to the first electrode layer and a second power terminal electrically connected to the second electrode layer, focusing multiple bundles of charged particles onto the object to be patterned using the electrostatic lens arranged in the beam path of the charged particles further includes: applying a first voltage to the first electrode layer through the first power terminal; and applying a second voltage, which is not equal to the first voltage, to the second electrode layer through the second power terminal.

[0053] In other words, voltage can be applied simultaneously to the first electrode layer and the second electrode layer of the first lens, the second lens, and other lenses in an electrostatic lens.

[0054] In a possible implementation of the fourth aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0055] In this case, the electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0056] In a possible implementation of the fourth aspect, the first part of the second electrode layer protrudes towards the first electrode layer relative to the second part of the second electrode layer. Along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, and the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

[0057] The electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is the same as the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0058] In a possible implementation of the fourth aspect, the first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

[0059] Thus, the electric field distribution when the first charged particle beam in the multi-splitter passes through the connected first and third holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the connected second and fourth holes.

[0060] In a possible implementation of the fourth aspect, the first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

[0061] Similarly, the electric field distribution when the first charged particle beam in a multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in a multi-splitter passes through the second and fourth interconnected holes.

[0062] Fifthly, this application provides an electrostatic lens, comprising: a first electrode layer, a second electrode layer, a first power terminal, a second power terminal, a third power terminal, and a fourth power terminal; wherein the first electrode layer and the second electrode layer are stacked and insulated from each other; the first electrode layer includes a first portion and a second portion, which are insulated from each other; the second electrode layer includes a first portion and a second portion, which are insulated from each other; the first portion and the second portion are arranged along a stacking direction; a first hole penetrating the first electrode layer along the stacking direction is formed in the first portion of the first electrode layer, and a second hole penetrating the first electrode layer along the stacking direction is formed in the second portion of the first electrode layer; a third hole communicating with the first hole is formed in the first portion of the second electrode layer, and a fourth hole communicating with the second hole is formed in the second portion of the second electrode layer; the first power terminal is electrically connected to the first portion of the first electrode layer. The second power terminal is electrically connected to the second part of the first electrode layer; the third power terminal is electrically connected to the first part of the second electrode layer; and the fourth power terminal is electrically connected to the second part of the second electrode layer.

[0063] In the electrostatic lens provided in this application embodiment, the first electrode layer is divided into an insulating and isolated first electrode layer first part and a first electrode layer second part, and the second electrode layer is divided into an insulating and isolated second electrode layer first part and a second electrode layer second part. That is to say, the first electrode layer first part, the first electrode layer second part, the second electrode layer first part, and the second electrode layer second part are independent structures. In addition, each part has a corresponding power supply terminal for providing voltage. Therefore, the voltage values ​​applied to each part do not interfere with each other. The field curvature correction of the first lens formed by the first electrode layer first part carrying the first hole and the second electrode layer first part carrying the third hole, and the field curvature correction of the second lens formed by the first electrode layer second part carrying the second hole and the second electrode layer second part carrying the fourth hole are independent of each other.

[0064] This embodiment allows for adjustment of the voltage in different parts to flexibly control field curvature correction, resulting in greater flexibility and wider applicability of field curvature correction.

[0065] In a possible implementation of the fifth aspect, the first portion of the first electrode layer and the second portion of the first electrode layer are located in a first plane, the first portion of the second electrode layer and the second portion of the second electrode layer are located in a second plane, and both the first plane and the second plane are perpendicular to the stacking direction.

[0066] In this case, the distance between the first part of the first electrode layer and the first part of the second electrode layer is equal to the distance between the second parts of the first electrode layer and the second part of the second electrode layer. That is, the field intensity distribution of the first lens and the second lens is the same.

[0067] In one possible implementation of the fifth aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0068] This can be understood as follows: when the apertures of the first and second holes are not equal, the larger the aperture, the smaller the difference in field strength on both sides of the hole, the weaker the ability to converge the charged particle beam, and the farther the focal point.

[0069] When the diameters of the first and second holes are not equal, and this is combined with the above-mentioned adjustment of the field strength by adjusting the voltage, the field curvature can be corrected.

[0070] In a possible implementation of the fifth aspect, the diameter of the first hole is equal to the diameter of the third hole; and / or, the diameter of the second hole is equal to the diameter of the fourth hole.

[0071] In a possible implementation of the fifth aspect, the electrostatic lens further includes a third electrode layer and a fourth electrode layer, with the first, second, third, and fourth electrode layers stacked sequentially. The third electrode layer includes a first portion and a second portion. The first portion of the third electrode layer has a fifth hole connected to a third hole, and the second portion has a sixth hole connected to a fourth hole. The fourth electrode layer includes a first portion and a second portion. The first portion of the fourth electrode layer has a seventh hole connected to a fifth hole, and the second portion has an eighth hole connected to a sixth hole. Furthermore, the first portion of the third electrode layer is electrically connected to a fifth power terminal, the second portion is electrically connected to a sixth power terminal, the first portion of the fourth electrode layer is electrically connected to a seventh power terminal, and the second portion of the fourth electrode layer is electrically connected to an eighth power terminal.

[0072] When using a first, second, third, and fourth electrode layer stacked in phase, voltage can be applied to different parts of different electrode layers to achieve field curvature correction by adjusting the object distance.

[0073] In a possible implementation of the fifth aspect, the electrostatic lens further includes: a first dielectric layer and a second dielectric layer, and a first electrode layer, the first dielectric layer and the second electrode layer are stacked sequentially along the stacking direction; the first dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole; the first part of the first electrode layer and the second part of the first electrode layer, as well as the first part of the second electrode layer and the second part of the second electrode layer, are all separated by the second dielectric layer.

[0074] In other words, by embedding the first dielectric layer and the second dielectric layer, insulation between the first electrode layer and the second electrode layer, insulation between the first part of the first electrode layer and the second part of the first electrode layer, and insulation between the first part of the second electrode layer and the second part of the second electrode layer are achieved.

[0075] In a sixth aspect, this application provides a multi-beam charged particle system, wherein the electrostatic lens includes a particle source and an electrostatic lens provided in any implementation of the fifth aspect above, and the electrostatic lens is arranged in the beam path of the charged particles.

[0076] The multi-beam charged particle system provided in this application includes the electrostatic lens of the fifth aspect embodiment. Therefore, the multi-beam charged particle system provided in this application and the electrostatic lens of the above-mentioned technical solutions can solve the same technical problems and achieve the same expected effects, and will not be described again here.

[0077] In a possible implementation of the sixth aspect, the multi-beam charged particle system is a multi-beam charged particle inspection system, such as a scanning electron microscope. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes: a stage for mounting the object to be inspected, and a detector, wherein the multi-beam charged particles after passing through the electrostatic lens are focused on the object to be inspected; the detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

[0078] For example, the electrostatic lens mentioned above is used in scanning electron microscopes. In this way, by applying different voltages to different areas of different electrode layers, the charged particle beams focused by the electrostatic lens will converge on the object to be inspected mounted on the stage, such as the wafer to be inspected. Compared with existing multi-beam charged particle systems, it can more comprehensively and quickly detect defects on the object to be inspected.

[0079] In a possible implementation of the sixth aspect, the multi-beam charged particle system is a multi-beam charged particle patterning system, such as an electron beam exposure machine. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes a stage for mounting the object to be patterned. The multi-beam charged particles after passing through the electrostatic lens are focused on the object to be patterned, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be patterned.

[0080] For example, the electrostatic lens mentioned above is used in an electron beam exposure machine. In this way, by applying different voltages to different areas of different electrode layers, the charged particle beams focused by the electrostatic lens will all converge on the object to be etched on the stage. Compared with the existing multi-beam charged particle system, this can improve the etching efficiency and shorten the etching time.

[0081] In a seventh aspect, this application provides a method for inspecting a substrate using multi-beam charged particles. The method includes: generating charged particles using a particle source; focusing the multi-beam charged particles onto the substrate using an electrostatic lens disposed in the beam path of the charged particles; and detecting secondary charged particles generated from the substrate by the multi-beam charged particles to generate a signal corresponding to the secondary charged particles. The electrostatic lens used here can be the electrostatic lens provided in any embodiment of the fifth aspect.

[0082] The method for multi-beam charged particle inspection of a substrate provided in this application includes the electrostatic lens of the fifth aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above-described technical solution can solve the same technical problem and achieve the same expected effect.

[0083] In one possible implementation of the seventh aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0084] In this case, the electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0085] Eighthly, this application provides a method for etching on an object coated with an anti-corrosion agent, the method comprising: generating charged particles using a particle source; and focusing multiple beams of charged particles onto the object to be etched using an electrostatic lens disposed in the beam path of the charged particles, thereby forming a particle beam spot on the object to be etched. The electrostatic lens here may be the electrostatic lens provided in any embodiment of the fifth aspect.

[0086] The method for engraving on an object coated with an anti-corrosion agent provided in this application includes the electrostatic lens of the fifth aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above technical solution can solve the same technical problem and achieve the same expected effect.

[0087] In one possible implementation of the eighth aspect, the diameter of the first hole is not equal to the diameter of the second hole.

[0088] In this case, the electric field distribution when the first charged particle beam in the multi-splitter passes through the first and third interconnected holes is different from the electric field distribution when the second charged particle beam in the multi-splitter passes through the second and fourth interconnected holes.

[0089] Ninthly, this application provides an electrostatic lens, comprising: a first electrode layer and a second electrode layer, the first electrode layer and the second electrode layer being stacked and insulated from each other; the first electrode layer comprising a first portion and a second portion; the second electrode layer comprising a first portion and a second portion; the first portion and the first portion of the first electrode layer being arranged along a stacking direction, and the second portion of the first electrode layer being arranged along a stacking direction; a first hole penetrating the first electrode layer along the stacking direction is formed in the first portion of the first electrode layer, and a second hole penetrating the first electrode layer along the stacking direction is formed in the second portion of the first electrode layer; a third hole communicating with the first hole is formed in the first portion of the second electrode layer, and a fourth hole communicating with the second hole is formed in the second portion of the second electrode layer; wherein the diameter of the first hole and the diameter of the second hole are not equal.

[0090] In the electrostatic lens provided in this application embodiment, since the apertures of the first hole and the second hole are not equal, the larger the aperture, the smaller the field strength difference on both sides of the hole, the weaker the focusing ability of the charged particle beam, and the farther the focal point. In this way, the field curvature can be adjusted to achieve the purpose of flattening the focusing surface of the multi-beam charged particle system.

[0091] In a possible implementation of the ninth aspect, the diameter of the first hole is equal to the diameter of the third hole; and / or, the diameter of the second hole is equal to the diameter of the fourth hole.

[0092] In a possible implementation of the ninth aspect, the first portion of the first electrode layer and the second portion of the first electrode layer are located in a first plane, the first portion of the second electrode layer and the second portion of the second electrode layer are located in a second plane, and both the first plane and the second plane are perpendicular to the stacking direction.

[0093] This can be understood as follows: the first part of the first electrode layer where the first hole is located and the second part of the first electrode layer where the second hole is located are planar structures perpendicular to the stacking direction. If the first part of the first electrode layer that carries the first hole and the second part of the first electrode layer that carries the second hole are not planar structures, the electric field around the first hole will be asymmetrical. In addition, the electric field around the second hole will also be asymmetrical. When charged particles pass through holes with asymmetrical electric fields, their trajectories will be deflected, thus failing to achieve the preset focusing effect.

[0094] In a possible implementation of the ninth aspect, the electrostatic lens further includes a dielectric layer, and the first electrode layer, the dielectric layer and the second electrode layer are stacked sequentially along the stacking direction; the dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole.

[0095] That is, insulation between the first electrode layer and the second electrode layer is achieved by embedding a dielectric layer.

[0096] In a possible implementation of the ninth aspect, the electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer; and the second power terminal is electrically connected to the second electrode layer.

[0097] In this way, when a voltage is applied to the first electrode layer, the voltage of the first part of the first electrode layer and the voltage of the second part of the first electrode layer are equal. Similarly, when a voltage is applied to the second electrode layer, the voltage of the first part of the second electrode layer and the voltage of the second part of the second electrode layer are equal. Compared with setting a power terminal for each part, the embodiment given in this application is more convenient for control.

[0098] In a tenth aspect, this application provides a multi-beam charged particle system, wherein the electrostatic lens includes a particle source and an electrostatic lens provided in any implementation of the ninth aspect above, the electrostatic lens being arranged in the beam path of the charged particles.

[0099] The multi-beam charged particle system provided in this application includes the electrostatic lens of the ninth aspect embodiment. Therefore, the multi-beam charged particle system provided in this application and the electrostatic lens of the above-mentioned technical solutions can solve the same technical problems and achieve the same expected effects, and will not be described again here.

[0100] In one possible implementation of the tenth aspect, the multi-beam charged particle system is a multi-beam charged particle inspection system, such as a scanning electron microscope. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes: a stage for mounting the object to be inspected, and a detector, wherein the multi-beam charged particles after passing through the electrostatic lens are focused on the object to be inspected; the detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

[0101] For example, when the aforementioned electrostatic lens is used in a scanning electron microscope, the charged particle beams focused by the electrostatic lens converge onto the object to be inspected mounted on the stage, such as the wafer to be inspected. Compared with existing multi-beam charged particle systems, this can more comprehensively and quickly detect defects on the object to be inspected.

[0102] In one possible implementation of the tenth aspect, the multi-beam charged particle system is a multi-beam charged particle patterning system, such as an electron beam exposure machine. In addition to the electrostatic lens and particle source mentioned above, the multi-beam charged particle inspection system also includes a stage for mounting the object to be patterned. The multi-beam charged particles after passing through the electrostatic lens are focused on the object to be patterned, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be patterned.

[0103] For example, if the electrostatic lens mentioned above is used in an electron beam exposure machine, the charged particle beams focused by the electrostatic lens will all converge on the object to be etched on the stage. Compared with the existing multi-beam charged particle system, this can improve the etching efficiency and shorten the etching time.

[0104] Eleventhly, this application provides a method for inspecting a substrate using multi-beam charged particles. The method includes: generating charged particles using a particle source; focusing the multi-beam charged particles onto the substrate using an electrostatic lens disposed in the beam path of the charged particles; and detecting secondary charged particles generated from the substrate by the multi-beam charged particles to generate a signal corresponding to the secondary charged particles. The electrostatic lens used here can be the electrostatic lens provided in any embodiment of the ninth aspect.

[0105] The method for multi-beam charged particle inspection of a substrate provided in this application includes the electrostatic lens of the ninth aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above technical solution can solve the same technical problem and achieve the same expected effect, and will not be described again here.

[0106] In one possible implementation of the eleventh aspect, when the electrostatic lens further includes a first power terminal electrically connected to the first electrode layer and a second power terminal electrically connected to the second electrode layer, focusing multiple bundles of charged particles onto the object to be patterned using the electrostatic lens arranged in the beam path of the charged particles further includes: applying a first voltage to the first electrode layer through the first power terminal; and applying a second voltage, which is not equal to the first voltage, to the second electrode layer through the second power terminal.

[0107] In other words, voltage can be applied simultaneously to the first electrode layer and the second electrode layer of the first lens, the second lens, and other lenses in an electrostatic lens.

[0108] In a twelfth aspect, this application provides a method for etching on an object coated with an anti-corrosion agent, the method comprising: generating charged particles using a particle source; and focusing multiple beams of charged particles onto the object to be etched using an electrostatic lens disposed in the beam path of the charged particles, thereby forming a particle beam spot on the object to be etched. The electrostatic lens here may be the electrostatic lens provided in any embodiment of the ninth aspect.

[0109] The method for engraving on an object coated with an anti-corrosion agent provided in this application includes the electrostatic lens of the ninth aspect embodiment. Therefore, the method provided in this application and the electrostatic lens of the above-described technical solution can solve the same technical problem and achieve the same expected effect.

[0110] In a possible implementation of the twelfth aspect, when the electrostatic lens further includes a first power terminal electrically connected to the first electrode layer and a second power terminal electrically connected to the second electrode layer, focusing multiple bundles of charged particles onto the object to be patterned using the electrostatic lens arranged in the beam path of the charged particles further includes: applying a first voltage to the first electrode layer through the first power terminal; and applying a second voltage, which is not equal to the first voltage, to the second electrode layer through the second power terminal.

[0111] In other words, voltage can be applied simultaneously to the first electrode layer and the second electrode layer of the first lens, the second lens, and other lenses in an electrostatic lens. Attached Figure Description

[0112] Figure 1 This is a structural diagram of a multi-beam charged particle system in the prior art;

[0113] Figure 2 For showing Figure 1 The structure of the virtual source positions in a multi-beam charged particle system;

[0114] Figure 3 For showing Figure 1 The focusing surface of the multi-beam charged particle system in the image is a curved surface;

[0115] Figure 4 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0116] Figure 5a and Figure 5b Used to illustrate the focusing principle of an electrostatic lens;

[0117] Figure 6 Figure (a) and Figure 6 Figure (b) in the diagram is used to illustrate the Gaussian imaging theorem;

[0118] Figure 7 This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0119] Figure 8 for Figure 7 Enlarged view of point X;

[0120] Figure 9 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0121] Figure 10a and Figure 10b This is a comparison diagram of the imaging of an electrostatic lens according to an embodiment of this application and a conventional electrostatic lens;

[0122] Figure 11a and Figure 11bThis is a comparison diagram of the imaging of an electrostatic lens according to an embodiment of this application and a conventional electrostatic lens;

[0123] Figure 12a and Figure 12b This is a comparison diagram of the imaging of an electrostatic lens according to an embodiment of this application and a conventional electrostatic lens;

[0124] Figure 13a and Figure 13b This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0125] Figure 14 This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0126] Figure 15 for Figure 14 A schematic diagram of the focusing principle;

[0127] Figure 16a and Figure 16b This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0128] Figure 17a and Figure 17b This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0129] Figure 18 Figure (a) and Figure 18 Figure (b) in the middle and Figure 18 Figure (c) is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0130] Figure 19 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0131] Figure 20 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0132] Figure 21 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0133] Figure 22 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0134] Figure 23 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0135] Figure 24 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0136] Figure 25 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0137] Figure 26 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0138] Figure 27 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0139] Figure 28a and Figure 28b as well as Figure 28c This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0140] Figure 29 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0141] Figure 30 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0142] Figure 31 for Figure 30 M-direction view;

[0143] Figure 32 for Figure 30 N-direction view;

[0144] Figure 33 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0145] Figure 34 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0146] Figure 35 This is a partial structural schematic diagram of the electrostatic lens according to an embodiment of this application;

[0147] Figure 36 This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0148] Figure 37 This is a schematic diagram of the electrostatic lens structure according to an embodiment of this application;

[0149] Figure 38 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0150] Figure 39 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0151] Figure 40 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0152] Figure 41 This is a schematic diagram of the structure of a multi-beam charged particle system according to an embodiment of this application;

[0153] Figure 42 This is a schematic diagram of the structure of the particle optical characterization system according to an embodiment of this application;

[0154] Figure 43 This is a schematic diagram of the structure of the particle optical inspection system according to an embodiment of this application.

[0155] Figure label:

[0156] 1-Particle source; 2-Collider; 200-Electrode layer; 300-Aperture; 3-1-Beam splitter; 4-First focusing lens; 5-Second focusing lens; 6-Biased device; 7-Object; 8-Detector; 9-Station; 100-Electrostatic lens; 101A-First electrostatic lens; 102A-Second electrostatic lens; 11, 1001-First electrode layer; 12, 1002-Second electrode layer; 21, 201-First aperture; 22, 202-Second aperture; 203-Third aperture; 204-Fourth aperture; 3-2-Dielectric layer; A1-First part of first electrode layer; A2-Second part of first electrode layer; B1-First part of second electrode layer; B2-Second part of second electrode layer. Detailed Implementation

[0157] This application provides a multi-beam charged particle system that can be used for microscopic imaging, such as in a scanning electron microscope (SEM). In addition to the multi-beam charged particle system, the SEM may also include detection elements, such as detectors. Such an SEM can be used to inspect objects, for example, to inspect semiconductor wafers for process defects. The specific inspection process can be as follows: the electron beam generated by the multi-beam charged particle system is focused onto the wafer to form an electron beam spot. The detector collects secondary electrons and backscattered electrons generated on the wafer surface, obtaining morphological information and atomic number characterization information of the wafer surface. This information is based on the fact that different atomic number materials have different secondary electron yields, and different surface morphologies result in different electron reflection angles and numbers, which are reflected in the image as distinct bright and dark areas. Furthermore, the electron image information can be used to determine whether the wafer surface has defects, whether the etching pattern is complete, and so on.

[0158] In addition, multi-beam charged particle systems can also be used in electron beam lithography machines. For example, in the manufacturing of semiconductor devices and integrated circuits, it is necessary to form the required patterns on the wafer. These patterns can be obtained by exposure and development using an electron beam lithography machine.

[0159] In the multi-beam charged particle system described above, other types of charged particles can be used instead of electrons, such as ions (e.g., helium ions), positrons, or myons.

[0160] Figure 4 A structural diagram of a multi-beam charged particle system is provided. This system may include a particle source 1, which is a particle generator structure capable of producing charged particles. The specific types of charged particles can be referred to the charged particle types described above. Figure 4 The diagram shows a particle source, and the resulting multi-beam charged particle system can be called a single charged-particle source or a multi-beam charged particle system.

[0161] In a single-charged-particle source multi-beam charged particle system, the multi-beam charged particle system also includes Figure 4 The collimator 2 and the aperture array 3-1 shown are arranged sequentially along the beam path of the charged particles generated by the particle source 1. The collimator 2 has the functions of beam expansion and collimation, and the aperture array 3-1 can split the charged particle beam after it has been expanded and collimated by the collimator 2 into multiple charged particle beams.

[0162] In some alternative implementations, such as Figure 4 The collimator 2 can be an electron lens structure, meaning it is formed by stacking at least two electrode layers 200, with a large-diameter aperture 300 formed in the stacked electrode layers 200. By applying different voltages to adjacent stacked electrode layers 200, an electric field is created. Thus, when a charged particle beam generated by the particle source 1 passes through the aperture 300, beam expansion and collimation functions can be achieved. For example, combined with… Figure 4 A higher voltage is applied to the middle electrode layer 200 in the collimator than to the other electrode layers, resulting in a divergent electric field region near the middle electrode layer 200. When electrons pass through this divergent electric field region, they are subjected to an electric force from the center to the edge, causing the electron beam to diverge outward, thus achieving the beam expansion function. A lower voltage is applied to the bottom electrode layer 200 in the collimator than to the middle electrode layer 200, resulting in a converging electric field region near the bottom electrode layer 200. When electrons pass through this converging electric field region, they are subjected to an electric force from the edge to the center, causing the electron beam to converge towards the center, thus achieving the collimation function.

[0163] In collimator 2, because the aperture of the hole 300 penetrating the electrode layer 200 is relatively large, thus, as Figure 4 As shown, in collimator 2, the force exerted on the charged particle beam is different at different positions from the central axis L. This results in field curvature. If the field curvature is not corrected, the focal plane where the multiple charged particle beams passing through beam splitter 3-1 converge is... Figure 3 The curved surface structure shown, regardless of whether this multi-beam charged particle system is applied to microscopic imaging, electron etching, or mask repair, will affect the resolution due to its focal plane. For example, when applying a multi-beam charged particle system with a curved focal plane to semiconductor wafer process defect detection, it cannot clearly reflect defect characteristics, thus reducing the detection effect. Therefore, flattening the focal plane as shown... Figure 4 The planar focal plane shown is the target in this field, and can also be combined with Figure 3 This means that the distance between the focal point and the target point is the defocus distance. By correcting the defocus of each focal point to zero, the focal plane can be flattened into a plane.

[0164] To eliminate defocus at the focal point and flatten the focal plane into a plane, such as... Figure 4 As shown, this application provides an electrostatic lens 100, which serves as a focusing lens and can be positioned on the beam path of the charged particle beam after passing through the beam splitter 3-1. In addition to achieving focusing, the electrostatic lens 100 can correct defocusing to achieve a plane focusing surface.

[0165] The electrostatic lens 100 involved in this application will be described in detail below with reference to the accompanying drawings.

[0166] Before explaining the feasible structure of the electrostatic lens 100, let's first combine... Figure 5a and Figure 5b The focusing principle of electrostatic lenses is explained.

[0167] Combination Figure 5a and Figure 5b , Figure 5a This is a partial structural diagram of an electrostatic lens, viewed from top view. Figure 5b yes Figure 5a The cross-sectional view of AA, by Figure 5b As can be seen, the electrostatic lens mainly includes a first electrode layer 11 and a second electrode layer 12. Both the first electrode layer 11 and the second electrode layer 12 are made of conductive materials, such as metal. The first electrode layer 11 and the second electrode layer 12 are insulated from each other. The first electrode layer 11 has a hole 21, and the second electrode layer 12 has a hole 22 that communicates with the hole 21.

[0168] It should be noted that this application does not limit the edge shape of the electrostatic lens, and is not limited to it. Figure 5a The shape shown is not particularly limited, nor is the arrangement of the multiple holes in the electrostatic lens for passing through charged particle beams particularly restricted. Figure 5a This is merely an illustrative example and is not intended to be limiting. Figure 5a The arrangement shown is as follows.

[0169] like Figure 5b The focusing principle of an electrostatic lens is as follows: when a first voltage V11 is applied to the first electrode layer 11, and a first voltage V22, which is not equal to the first voltage V11, is applied to the second electrode layer 12, an electric field E is formed. For example, in Figure 5b In this example, a voltage of 10 kV is applied to the first electrode layer 11 and a voltage of 3 kV is applied to the second electrode layer 12. Figure 5b The diagram shows the electric field line E, and the equipotential lines (such as...). Figure 5b (As shown by the dashed line), the region between the first electrode layer 11 and the second electrode layer 12 and near the center is a uniform electric field (as shown by the dashed line). Figure 5b (The dashed line in the middle represents a straight line), however, there are non-uniform electric fields near holes 21 and 22 (such as...). Figure 5b (The dashed line in the figure is a curve) Assuming that when electrons move from upstream of the first electrode layer 11 to point A, they will be subjected to an electric field force F in the direction shown in the figure. This electric field force F can be decomposed into F10 and F20, which are perpendicular to each other. Under the action of the electric field force F10, the electron beam can be converged, thus achieving the focusing function.

[0170] Figure 6 Figure (a) and Figure 6 Figure (b) illustrates the Gaussian imaging theorem. The structural diagram shows that the electrostatic lens 100 can be based on... Figure 6 Figure (a) and Figure 6 The mechanism shown in Figure (b) is formed, in which, Focal length For object distance, For image distance, in Figure 6 The focal length of the first lens shown in Figure (a) and Figure 6 The focal length of the second lens shown in Figure (b) When they are equal, the object distance of the lens can be adjusted. Change image distance , combined Figure 6 Figure (a) and Figure 6 In diagram (b), when the object distance is... Figure 6 In Figure (a) Increase , become Figure 6 In Figure (b) At that time, the image distance will change from Figure 6 In Figure (a) Become Figure 6 Figure (b) Therefore, the change in the focal point is By adjusting the inconsistency between the rates of change of object distance and phase distance, the focal point of the charged particle beam can be adjusted. The focal point position is determined by... Figure 6 In Figure (a), F01 becomes Figure 6 F02 in Figure (b).

[0171] Figure 7 Based on the Gaussian imaging theorem mentioned above A structural diagram of an electrostatic lens 100 is shown. Figure 8 yes Figure 7 The magnified image at point X, combined with Figure 7 and Figure 8 The electrostatic lens 100 includes a first electrode layer 1001 and a second electrode layer 1002 stacked together, and the first electrode layer 1001 and the second electrode layer 1002 are separated by a dielectric layer 3-2 to achieve insulation between the two electrode layers, thereby preventing the first electrode layer 1001 and the second electrode layer 1002 from being electrically connected.

[0172] Continue to combine Figure 7 and Figure 8 The first electrode layer 1001 includes a first part A1 and a second part A2. The first part A1 has a first hole 201 that penetrates the first electrode layer 1001, and the second part A2 has a second hole 202 that penetrates the first electrode layer 1001.

[0173] Combined Figure 7 and Figure 8 The second electrode layer 1002 includes a first part B1 and a second part B2. The first part B1 has a third hole 203 that penetrates the second electrode layer 1002, and the second part B2 has a fourth hole 204 that penetrates the second electrode layer 1002.

[0174] Continue to combine Figure 7 and Figure 8 The first part A1 of the first electrode layer and the first part B1 of the second electrode layer are arranged vertically along the stacking direction P. The second part A2 of the first electrode layer and the second part B2 of the second electrode layer are also arranged vertically along the stacking direction P. In addition, the first hole 201 and the third hole 203 are connected, and the second hole 202 and the fourth hole 204 are connected.

[0175] This can be understood as follows: Figure 8 The electrostatic lens includes a first lens and a second lens. The first lens includes a first portion A1 of a first electrode layer carrying a first hole 201 and a first portion B1 of a second electrode layer carrying a third hole 203. The second lens includes a second portion A2 of a first electrode layer carrying a second hole 202 and a second portion B2 of a second electrode layer carrying a fourth hole 204.

[0176] Combined Figure 8 The first part A1 of the first electrode layer protrudes away from the second part A2 of the first electrode layer in a direction away from the second electrode layer 1002. Also, the first part B1 of the second electrode layer protrudes towards the first electrode layer 1001 relative to the second part B2 of the second electrode layer.

[0177] In some embodiments, combined with Figure 9 This allows the distance *d* between the port of the first aperture 201 near the third aperture 203 and the port of the third aperture 203 near the first aperture 201 to be equal to the distance *d* between the port of the second aperture 202 near the fourth aperture 204 and the port of the fourth aperture 204 near the second aperture 202. In this way, the focal length of the formed first lens is... The second lens equal.

[0178] The following explains the projection of the first portion A1 of the first electrode layer relative to the second portion A2 of the first electrode layer in a direction away from the second electrode layer 1002: The first portion A1 of the first electrode layer has two opposing surfaces, which can be defined as a first surface and a second surface. The second portion A2 of the first electrode layer has two opposing surfaces, which can be defined as a third surface and a fourth surface. The projection of the first portion A1 of the first electrode layer relative to the second portion A2 of the first electrode layer in a direction away from the second electrode layer 1002 means that there is a gap between the first surface and the third surface along the stacking direction P, and there is a gap between the second surface and the fourth surface along the stacking direction P.

[0179] Due to the focal length of the first lens The second lens Furthermore, since the first lens protrudes relative to the second lens, if this electrostatic lens 100 is applied to a multi-beam charged particle system, the first lens is closer to the particle source relative to the second lens. Compared to existing structures where the first and second lenses are on the same plane, this changes the object distance of the first lens. and the object distance of the second lens According to the Gaussian imaging theorem This will change the image distance V of the first lens. The image distance V of the first lens In this case, the following will occur Figure 8 and Figure 9 The focal point F1 of the first lens and the focal point F2 of the second membrane aperture lens shown are not on the same straight line.

[0180] Figure 10a and Figure 10b A schematic diagram of electrostatic lens correction is given, such as... Figure 10a When the existing uncorrected focal plane is concave, a method including... Figure 8 and Figure 9 The electrostatic lens 100 with the structure shown is made of Figure 10b It can be seen that the convex electrostatic lens 100 can perform reverse compensation on the focal plane to be corrected, so as to flatten the focal plane into a plane.

[0181] The convex shape of an electrostatic lens needs to be determined based on the shape of the focal surface to be corrected. Figure 11b and Figure 12b Two convex shapes for electrostatic lenses are given.

[0182] for example, Figure 11a When the existing uncorrected focal plane is convex, it can be used Figure 11b The electrostatic lens 100 shown is an electrostatic lens that, through... Figure 11b The concave electrostatic lens 100 shown can perform reverse compensation on the focal plane to be corrected, so as to flatten the focal plane.

[0183] For example, Figure 12a When the existing uncorrected focal surface is a wavy surface with convex and concave surfaces, it can be used as follows: Figure 12b The electrostatic lens 100 shown is an electrostatic lens that, through... Figure 12b The wavy electrostatic lens 100 shown can perform reverse compensation on the focal plane to be corrected, so as to flatten the focal plane.

[0184] In the above Figure 10b , Figure 11b and Figure 12b The electrostatic lens 100 shown includes three electrode layers, but it can also have two or more electrode layers. The more electrode layers there are, the more controllable voltages are available, making adjustment easier. At the same voltage, the electrostatic lens can adjust a wider defocus range, resulting in better applicability.

[0185] Figure 13aThe diagram shows a structure in which the first part A1 of the first electrode layer protrudes relative to the second part A2 of the first electrode layer, and the first part B1 of the second electrode layer protrudes relative to the second part B2 of the second electrode layer. That is, the first part A1 and the second part A2 of the first electrode layer are both planar structures perpendicular to the stacking direction P. Similarly, the first part B1 and the second part B2 of the second electrode layer are also planar structures perpendicular to the stacking direction P.

[0186] Figure 13b Another structure is shown, in which the first part A1 of the first electrode layer protrudes relative to the second part A2 of the first electrode layer, and the first part B1 of the second electrode layer protrudes relative to the second part B2 of the second electrode layer. That is, any part of the first part A1, the first part A2, the first part B1, or the second part B2 of the second electrode layer is an inclined surface structure that is not perpendicular to the stacking direction P.

[0187] In other alternative embodiments, any portion of the first portion A1 of the first electrode layer, the second portion A2 of the first electrode layer, the first portion B1 of the second electrode layer, or the second portion B2 of the second electrode layer is not planar but has an arcuate structure. Of course, other protruding forms can also be used.

[0188] Figure 13a Compared to the convex form shown Figure 13b The convex shape shown, since both the first portion A1 and the second portion A2 of the first electrode layer are planar structures perpendicular to the stacking direction P, results in a symmetrical electric field distribution around the intersecting first hole 201 and third hole 203 about the central axis of the hole. Consequently, the electric force experienced by the charged particle beam passing through the first hole 201 and third hole 203 is symmetrical, thus preventing the occurrence of… Figure 13b The phenomenon shown is that the trajectory of the charged particle beam deviates from the expected path. Therefore, Figure 13a The convex shape shown can further improve image quality.

[0189] However, in the actual processing of the first part A1 of the first electrode layer, the second part A2 of the first electrode layer, the first part B1 of the second electrode layer, and the second part B2 of the second electrode layer, within the processing error range, it is sufficient to ensure that each part is a planar structure perpendicular to the stacking direction P.

[0190] Figure 14 This diagram illustrates the principle for forming another type of electrostatic lens, namely, electrostatic lens 100 can also be based on... Figure 14 The mechanism shown is formed in Figure 14In the first lens, the distance d between the first electrode layer 1001 and the second electrode layer 1002 is equal to the distance d between the first electrode layer 1001 and the second electrode layer 1002 of the second lens. The difference between the first lens and the second lens is that the aperture S1 of the first lens is larger than the aperture S2 of the second lens.

[0191] Figure 15 It shows Figure 14 The imaging principle of the structure shown is in Figure 15 In this process, when a first voltage, such as 10kV, is applied to the first electrode layer 1001, and a second voltage, such as 5kV, is applied to the second electrode layer 1002, the field strength distribution around the holes in the first and second lenses will differ because the apertures of the holes in the first and second lenses are different. Furthermore, the larger the aperture, the greater the difference in field strength. The smaller.

[0192] Based on relational , here To focus on distance, It is a constant. The kinetic energy of the charged particle beam as it passes through the aperture (in the same multi-beam charged particle system), (for a fixed value) For the difference in field strength, in Figure 15 In this case, because the aperture of the first lens is larger than the aperture of the second lens, the first lens... Smaller than the second lens Therefore, the first lens Larger than the second lens This is how it happened. Figure 15 The focal point of the first lens shown The second lens They are not on a straight line.

[0193] Figure 16a and Figure 16b Based on the above, Figure 14 and Figure 15 The mechanism shown illustrates the structure of an electrostatic lens 100. Figure 16b yes Figure 16a Top view, by Figure 16b As can be seen, the apertures formed in an electrostatic lens can be set to be unequal. Whether these apertures gradually increase or decrease along the central region towards the edge region depends on the size of the defocus to be corrected. Figure 16a and Figure 16b Only one exemplary structure is given.

[0194] Figure 17a and Figure 17b Another electrostatic lens structure is presented. Figure 17b yes Figure 17a The top view shows that the structure of the electrostatic lens 100 is based on the above. Figure 6 Figure (a) and Figure 6 The Gaussian imaging theorem is shown in Figure (b). and Figure 14 and Figure 15 It is formed by the imaging mechanism shown.

[0195] Figure 17a and Figure 17b The electrostatic lens structure shown includes three electrode layers, with each pair of electrode layers separated by a dielectric layer. These three electrode layers form a convex structure. In addition, as... Figure 17a and Figure 17b The holes formed in the electrostatic lens 100 are not completely equal.

[0196] The following is combined Figure 18 Figure (a) in the middle Figure 18 Figure (b) in the middle and Figure 18 Figure (c) in the middle, for Figure 17a and Figure 17b The advantages of the structure shown are analyzed, in Figure 18 Figure (a) in the middle Figure 18 Figure (b) in the middle and Figure 18 In Figure (c), Figure 18 The voltage V1 of the first electrode layer 1001 in Figure (a) and Figure 18 The voltage V1 of the first electrode layer 1001 in Figure (b), and Figure 18 In Figure (c), the voltage V1 of the first electrode layer 1001 is equal, and similarly, Figure 18 The voltage V2 of the second electrode layer 1002 in Figure (a) and Figure 18 The voltage V2 of the second electrode layer 1002 in Figure (b), and Figure 18 In Figure (c), the voltage V2 of the second electrode layer 1002 is equal. In addition, the distance between the first electrode layer 1001 and the second electrode layer 1002 is d.

[0197] Depend on Figure 18 Figure (a) and Figure 18 Compare with diagram (b) in the middle, when it is necessary to... Figure 18 In Figure (a), the focal point F1 of the first lens becomes... Figure 18 When the focal point of the lens in Figure (b) is F11, the first lens needs to protrude further from the second lens, which will result in the thickness P1 of the electrostatic lens in Figure (a) increasing to [a certain value]. Figure 18In Figure (b), P2 would cause the overall size of the electrostatic lens to increase along the stacking direction P. However, if... Figure 18 When the structure shown in Figure (c) is such that the aperture of the first lens is reduced from S to S1, the focal point F01 of the first lens can also be adjusted to the focal point F11. Figure 18 Figure (b) in the middle and Figure 18 Comparing with Figure (c), the size of the entire electrostatic lens along the stacking direction P remains unchanged, still being P1.

[0198] From another perspective Figure 18 Figure (a) in the middle Figure 18 Figure (b) in the middle and Figure 18 The advantages of the structure shown in Figure (c) are analyzed. For example, when the position of the focal point is adjusted by forming holes of different diameters, if the defocus is large, a larger diameter hole needs to be formed. In this case, the number of holes formed per unit area of ​​the electrostatic lens will be less. As a result, the number of charged particle beams coming out of the electrostatic lens will be reduced. If this multi-beam charged particle system is used for etching, the etching time will be extended and the work efficiency will be reduced.

[0199] To avoid having too few holes per unit area and to improve work efficiency, the difference in aperture can be reduced by making the lens protrude to change the object distance and adjust the focal point position.

[0200] Figure 19 A structural diagram of a multi-beam charged particle system is given. In addition to particle source 1, collimator 2, and beam splitter 3-1, the system also includes an electrostatic lens 100. This type of multi-beam charged particle system can be referred to as a multi-charged-particle beam or multi-optical-column multi-beam charged particle system.

[0201] exist Figure 19 In the multi-charged-particle beam multi-optical column system shown, there is one electrostatic lens 100, thus forming a multi-beam multi-column multi-beam charged particle system with a single focusing module. Furthermore, the electrostatic lens 100 here is based on the above... Figure 6 Figure (a) and Figure 6 The Gaussian imaging theorem is shown in Figure (b). ,and Figure 14 and Figure 15 It is formed by the imaging mechanism shown.

[0202] In some implementations, such as when the defocus difference is small, this approach can be adopted. Figure 19 The single focusing module shown adjusts the multi-charged-particle beam multi-optical column system to achieve flattening of the focusing plane.

[0203] Figure 20 A structural diagram of another multi-charged-particle beam multi-optical column system is provided. In this system, the electrostatic lenses include a first electrostatic lens 101A and a second electrostatic lens 102A, thus forming a multi-module adjustable multi-charged-particle beam multi-optical column system. Each of the first electrostatic lens 101A and the second electrostatic lens 102A is based on the above-described... Figure 6 Figure (a) and Figure 6 The Gaussian imaging theorem is shown in Figure (b). ,and Figure 14 and Figure 15 It is formed by the imaging mechanism shown.

[0204] In other implementations, for example, when the defocus difference is large, if the above-mentioned method is used... Figure 19 The multi-charged-particle beam multi-optical column system, as shown in the diagram, adjusts a single focusing module. This results in a significant difference between the aperture diameters of the edge region and the central region of the electrostatic lens. If the aperture size in the edge region is fixed, the aperture size in the central region needs to be reduced. This increases the manufacturing difficulty of the electrostatic lens and limits its adjustment capability. In this case, a different approach can be used... Figure 20 The multi-module adjustable multicharged-particle beam multi-optical column system shown in the figure can distribute the adjustment pressure of each electrostatic lens, thus enhancing adjustment flexibility.

[0205] Figure 21 This diagram illustrates the principle for forming another type of electrostatic lens, namely, electrostatic lens 100 can also be based on... Figure 21 The mechanism shown is formed in Figure 21In the first lens, the aperture S is equal to the aperture S of the second lens. The difference between the first lens and the second lens is that the distance d1 between the first electrode layer 1001 and the second electrode layer 1002 of the first lens is greater than the distance d2 between the first electrode layer 1001 and the second electrode layer 1002 of the second lens.

[0206] Based on relational ,as well as In the formula To focus on distance, It is a constant. The kinetic energy of the charged particle beam as it passes through the aperture (in the same multi-beam charged particle system), (for a fixed value) The voltage difference applied between the two electrode layers. This refers to the spacing between the two electrode layers. Figure 21 In this case, when the voltage applied to the first electrode layer 1001 of the first lens and the first electrode layer 1001 of the second lens is the same, similarly, the voltage applied to the second electrode layer 1002 of the first lens and the second electrode layer 1002 of the second lens is the same, and thus, the voltage applied to the first lens... , equal to the second lens However, because of the first lens Larger than the second lens Therefore, the first lens Smaller than the second lens Thus, the first lens can be obtained. Larger than the second lens This is how it happened. Figure 21 The focal point of the first lens shown The second lens They are not on a straight line.

[0207] Figure 22 A structure for an electrostatic lens 100 is provided, the structure of which is based on the above. Figure 21 It is formed by the imaging mechanism shown.

[0208] exist Figure 22 In the first electrode layer, the first part A1 protrudes away from the second electrode layer 1002 relative to the second part A2. The first part B1 and the second part B2 of the second electrode layer are in the same plane perpendicular to the stacking direction P. In this case, the distance d1 between the first part A1 and the first part B1 of the first electrode layer and the distance d2 between the second part A2 and the second part B2 of the second electrode layer are not equal.

[0209] Figure 23A structural diagram of a multi-charged-particle beam multi-optical-column system is presented. In addition to the particle source 1, collimator 2, and beam splitter 3-1, this system also includes an electrostatic lens 100. The electrostatic lens 100 here is based on the aforementioned... Figure 22 And thus formed.

[0210] Figure 24 A structure for an electrostatic lens 100 is provided, which is also based on the above-described structure. Figure 21 It is formed by the imaging mechanism shown.

[0211] exist Figure 24 In the first electrode layer, the first part A1 protrudes away from the second electrode layer 1002 relative to the second part A2. Similarly, the first part B1 of the second electrode layer protrudes towards the first electrode layer 1001 relative to the second part B2. However, the degree of protrusion of the first part A1 and the second part A2 of the first electrode layer is different, which makes the distance d1 between the first part A1 and the first part B1 of the second electrode layer and the distance d2 between the second part A2 and the second part B2 of the first electrode layer unequal.

[0212] Figure 25 A structure for an electrostatic lens 100 is provided, which is also based on the above-described structure. Figure 24 It is formed by the imaging mechanism shown.

[0213] exist Figure 25 In the first electrode layer, the first part A1 protrudes away from the second electrode layer 1002 relative to the second part A2, and the first part B1 of the second electrode layer protrudes away from the first electrode layer 1001 relative to the second part B2. In this case, the distance d1 between the first part A1 and the first part B1 of the first electrode layer is not equal to the distance d2 between the second part A2 and the second part B2 of the second electrode layer.

[0214] Figure 26 A structural diagram of a multi-charged-particle beam multi-optical-column system is presented. In addition to the particle source 1, collimator 2, and beam splitter 3-1, this system also includes an electrostatic lens 100. The electrostatic lens 100 here is based on the aforementioned... Figure 25 And thus formed.

[0215] In the above Figure 22 , Figure 24 and Figure 25 And in other electrostatic lenses shown, it can be used with Figure 15 The imaging mechanism shown (changing the aperture) is combined to form other electrostatic lenses, for example, Figure 27 It is in Figure 25 Based on this, the aperture S1 of the first lens is set to be smaller than the aperture S2 of the second lens.

[0216] The following is combined Figure 28a , Figure 28b and Figure 28c right Figure 27 The advantages of the structure shown are analyzed, in Figure 28a , Figure 28b and Figure 28c middle, Figure 28a The voltage V1 of the first electrode layer 1001 in the middle, and Figure 28b The voltage V1 of the first electrode layer 1001 in the middle, and Figure 28c The voltage V1 of the first electrode layer 1001 is equal, and similarly, Figure 28a The voltage V2 of the second electrode layer 1002 in the middle, and Figure 28b The voltage V2 of the second electrode layer 1002 in the middle, and Figure 28c The voltage V2 of the second electrode layer 1002 is equal. In addition, the distance between the first electrode layer 1001 and the second electrode layer 1002 is d.

[0217] Depend on Figure 28a and Figure 28b In contrast, when it is necessary to Figure 28a The focal point F01 of the first lens in the middle becomes Figure 28b When the focal point of the lens is F11, the distance between the first part and the second part of the first electrode layer in the first lens needs to be increased from d2 to d21, which will result in... Figure 28a The thickness P1 of the electrostatic lens in the middle is increased to Figure 28b In the case of P2, this would cause the overall size of the electrostatic lens to increase along the stacking direction P. However, if using... Figure 28c When the structure shown is such that the aperture of the first lens is reduced from S to S1, the focal point F01 of the first lens can be adjusted to the focal point F11. Figure 28a and Figure 28c In contrast, the size of the entire electrostatic lens along the stacking direction P remains unchanged, still being P1.

[0218] In the above embodiments, such as Figure 27 As shown, any one of the first, second, third, and fourth holes is a straight hole. A straight hole can also be interpreted as one whose diameter remains constant along its axial direction. In other embodiments, such as... Figure 29 As shown, any one of the first, second, third, and fourth holes is a wedge-shaped hole. A wedge-shaped hole can also be interpreted as one whose diameter changes linearly along its axial direction. Of course, holes can also be shaped, for example, with their diameter changing non-linearly along their axial direction.

[0219] Alternatively, the aperture of the first hole of the intersecting first lens and the aperture of the third hole of the second lens may be set to be equal, or the aperture of the second hole of the intersecting first lens and the aperture of the fourth hole of the second lens may be set to be equal, or the aperture of the first hole of the intersecting first lens and the aperture of the third hole of the second lens may be set to be equal, and the aperture of the second hole of the intersecting first lens and the aperture of the fourth hole of the second lens may be set to be equal.

[0220] In the electrostatic lens described above, the first electrode layer 1001 is connected to a first power supply terminal, and the second electrode layer 1002 is connected to a second power supply terminal. In this way, when a voltage is applied to the first electrode layer 1001 through the first power supply terminal, the same voltage can be applied to both the first part of the first electrode layer and the second part of the first electrode layer. Similarly, when a voltage is applied to the second electrode layer 1002 through the second power supply terminal, the same voltage can be applied to both the first part of the second electrode layer and the second part of the second electrode layer.

[0221] This application also provides another electrostatic lens structure different from the one described above, such as... Figure 30 As shown, the electrostatic lens 100 includes a first electrode layer 1001 and a second electrode layer 1002 stacked in phase, and the first electrode layer 1001 and the second electrode layer 1002 are insulated from each other, for example, by being separated by a dielectric layer 3-2, so as to avoid electrical connection between the first electrode layer 1001 and the second electrode layer 1002.

[0222] Combination Figure 31 , Figure 31 yes Figure 30 In the M-direction view, the first electrode layer 1001 includes a first portion A1 and a second portion A2. The first portion A1 has a first hole 201 penetrating through the first electrode layer 1001, and the second portion A2 has a second hole 202 penetrating through the first electrode layer 1001. Furthermore, the first portion A1 and the second portion A2 are insulated from each other, for example, by being separated by a dielectric layer 3-2, to prevent electrical connection between them. The first portion A1 is electrically connected to a first power supply terminal VO1, and the second portion A2 is electrically connected to a second power supply terminal VO2.

[0223] Combination Figure 32 , Figure 32 yes Figure 30 In the N-direction view, the second electrode layer 1002 includes a first portion B1 and a second portion B2. The first portion B1 has a third hole 203 penetrating through the second electrode layer 1002, and the second portion B2 has a fourth hole 204 penetrating through the second electrode layer 1002. Furthermore, the first portion B1 and the second portion B2 are insulated from each other, for example, by being separated by a dielectric layer 3-2, to prevent electrical connection between the two portions. The first portion B1 is electrically connected to a third power terminal VO3, and the second portion B2 is electrically connected to a fourth power terminal VO4.

[0224] Among them, such as Figure 30 The first part A1 of the first electrode layer and the first part B1 of the second electrode layer are arranged vertically along the stacking direction P. The second part A2 of the first electrode layer and the second part B2 of the second electrode layer are also arranged vertically along the stacking direction P. The first hole 201 and the third hole 203 are connected, and the second hole 202 and the fourth hole 204 are connected.

[0225] Figure 30 The difference between the electrostatic lens shown and any of the electrostatic lenses mentioned above is that: Figure 30 In this structure, each of the first electrode layer, the first part A1, the second part A2, the first part B1, and the second part B2 is connected to a power supply terminal. This allows different voltages to be applied to each of the first electrode layer, the first part A1, the second part A2, the first part B1, and the second part B2. Consequently, the voltage difference between the first electrode layer, the first part A1, and the second part B1 can be the same as or different from the voltage difference between the first electrode layer, the second part A2, and the second part B2. Consequently, the field strength of the first lens and the field strength of the second lens can be the same or different.

[0226] Therefore, in Figure 30In the electrostatic lens shown, the position of the focal point can be changed by controlling the voltage of different parts, thus giving the electrostatic lens strong flexibility and robustness, making it applicable to more scenarios. For example, by applying a voltage of 15kV to the first part A1 of the first electrode layer through the first power terminal V01, and applying a voltage of 8kV to the first part B1 of the second electrode layer through the third power terminal V03, the first lens can be placed in one electric field, thereby forming a focal point at one location. By applying a voltage of 10kV to the second part A2 of the first electrode layer through the second power terminal V02, and applying a voltage of 2kV to the second part B2 of the second electrode layer through the fourth power terminal V04, the second lens can be placed in another electric field, thereby forming a focal point at another location.

[0227] In particular, by applying different voltages to different parts according to different application scenarios, that is, according to different sizes of defocus, different shapes of focusing surfaces can be flattened.

[0228] In the above Figure 30 In the electrostatic lens shown, it can be used with Figure 15 The imaging mechanism shown (changing the aperture) is combined to form other electrostatic lenses, for example, Figure 33 It is in Figure 30 Based on this, the aperture S1 of the first lens is set to be smaller than the aperture S2 of the second lens.

[0229] In addition, Figure 30 and Figure 33 In the electrostatic lens shown, any one of the first, second, third, and fourth holes can be a straight hole, a wedge-shaped hole, or a hole of other shapes.

[0230] In some alternative embodiments, in addition to the first electrode layer 1001 and the second electrode layer 1002, more electrode layers may be included, for example, [the following may be specified]. Figure 34 The structure shown also includes a third electrode layer 1003 and a fourth electrode layer 1004. The first electrode layer 1001 and the second electrode layer 1002, the third electrode layer 1003 and the fourth electrode layer 1004 are stacked sequentially and separated by a dielectric layer 3-2 between each pair of adjacent electrode layers. In addition, the third electrode layer 1004 forms a first part and a second part of the third electrode layer, which are separated by the dielectric layer 3-2. The fourth electrode layer 1004 forms a first part and a second part of the fourth electrode layer, which are separated by the dielectric layer 3-2.

[0231] for Figure 34In the specific implementation of the electrostatic lens shown, a first voltage can be applied to the first part B1 of the second electrode layer 1002 and the second part C2 of the third electrode layer 1003, while a second voltage is applied to the first part C1 of the third electrode layer 1003 and the second part D2 of the fourth electrode layer 1004. The first voltage and the second voltage are not equal, and no voltage is applied to the remaining parts. That is, the first part B1 of the second electrode layer and the first part C1 of the third electrode layer constitute the first lens, and the second part C2 of the third electrode layer and the second part D2 of the fourth electrode layer constitute the second lens. The imaging mechanism of such an electrostatic lens can be described by the Gaussian imaging theorem. Explanation: Due to the focal length of the first lens The second lens They are equal. Furthermore, since the first lens bulges relative to the second lens, the object distance of the first lens is also equal. Object distance with the second membrane aperture lens The distances are not equal, so that the image distance of the first lens is not equal. Image distance of the second membrane aperture lens They are not equal, therefore, the following will occur Figure 35 The focal point F1 of the first lens and the focal point F2 of the second membrane aperture lens shown are not on the same straight line.

[0232] Figure 36 and Figure 37 The structural diagrams of an electrostatic lens are given, which includes six electrode layers. Figure 36 and Figure 37 It can be seen that the position of the focal point is different when voltage is applied to different parts of different electrode layers.

[0233] Figure 38 A structural diagram of a multi-charged-particle beam multioptical column system with a single focusing module is provided. In addition to the particle source 1, collimator 2, and beam splitter 3-1, this system also includes an electrostatic lens 100. The electrostatic lens 100 here is based on the aforementioned... Figure 36 or Figure 37 Furthermore, the apertures of each hole in the electrostatic lens 100 are equal.

[0234] Figure 39 A structural diagram of another multi-charged-particle beam multioptical column multi-splitter charged particle system with a single focusing module is given. Figure 38The difference in the multi-beam charged particle system shown is that the apertures of the individual holes in the electrostatic lens 100 can be unequal.

[0235] Figure 40 A structural diagram of another multi-charged-particle beam multioptical column multi-beam charged particle system with multiple focusing modules is given. The electrostatic lenses in this structure include a first electrostatic lens 101A and a second electrostatic lens 102A. The first electrostatic lens 101A is based on the aforementioned Gaussian imaging theorem. The second electrostatic lens 102A is formed based on the above. Figure 36 or Figure 37 And thus formed.

[0236] Figure 41 A structural diagram of another multi-charged-particle beam multioptical column multi-beam charged particle system with multiple focusing modules is given. The electrostatic lenses in this structure include a first electrostatic lens 101A and a second electrostatic lens 102A, both of which are based on the aforementioned... Figure 36 or Figure 37 And thus formed.

[0237] for Figure 40 and Figure 41 The multi-beam multi-column charged particle system shown, with its multiple focusing modules, offers enhanced capability for large-field curvature adjustment.

[0238] Based on the above description of the structure of multiple electrostatic lenses, this application can be summarized as including electrostatic lenses formed based on three different principles, as described below.

[0239] The first method is through the Gaussian imaging theorem. In other words, by making the surface of the electrostatic lens facing the particle source curved, the focusing position of the charged particle beam can be adjusted to reduce the difference in defocus between different charged particle beams, and ultimately the focusing surface can be flattened.

[0240] The second method involves changing the size of the aperture in the electrostatic lens used to allow the charged particle beam to pass through, thereby reducing the difference in defocus between different charged particle beams and achieving a flattened focusing surface.

[0241] The third method involves setting the electrostatic lens as a multi-layered electrode that is mutually insulated, with each electrode layer having multiple regions, and each adjacent region being insulated from the others. By applying different voltages to different regions of different layers, the defocusing difference of different charged particle beams is reduced, thus achieving a flattened focusing surface.

[0242] The electrostatic lens of any of the above embodiments can be used in chip manufacturing processes.

[0243] The chip manufacturing process is described below, mainly including the following steps: Step 1, fabricating a wafer; Step 2, coating the wafer surface with an anti-corrosion agent; Step 3, using a multi-beam charged particle system to irradiate the anti-corrosion agent with charged particle beams to form a pattern; Step 4, using an etching machine to etch N-wells and P-wells on the exposed silicon and implanting ions to form PN junctions (logic gates); Step 5, then using chemical and physical vapor deposition to create metal interconnect circuits, thereby obtaining the chip.

[0244] In the process of step three above, the wafer can be patterned using the patterning system with an electrostatic lens provided in this application, such as an electron beam lithography machine. Figure 42 A structural diagram of an etching system is provided. In addition to the aforementioned multi-beam charged particle system, the system includes a stage 9 for mounting the object 7 to be etched, such as a wafer. It also includes a deflector 6 for controlling the etching position on the wafer. When using... Figure 42 When the engraving system shown engraves the wafer, the particle source 1 generates charged particles, the collimator 2 then collimates and expands the charged particles, and the collimated and expanded charged particle beam is split into multiple beams by the beam splitter 3-1. The first electrostatic lens 101A and the second electrostatic lens 102A converge the multiple beams of charged particles, and under the action of the biaser 6, the charged particle beam is focused on the position on the wafer that needs to be engraved.

[0245] Since the first electrostatic lens 101A and the second electrostatic lens 102A can correct the defocus distance, the charged particle beams passing through the first electrostatic lens 101A and the second electrostatic lens 102A can be focused on the wafer to be engraved. Compared with the existing multi-beam charged particle systems with large defocus differences, this system can ensure that the charged particle beams are all focused on the wafer to be engraved, rather than partially focused on the wafer and partially focused on the top of the wafer. Therefore, the engraving system provided in this application can shorten the engraving time and improve the engraving efficiency.

[0246] After completing the chip manufacturing process described above, the following steps are included: Step 1, inspecting the chip to check for any manufacturing defects; Step 2, packaging the inspected chip. A testing system is required for Step 1. Figure 43 A structural diagram of an inspection system is provided. In addition to the aforementioned multi-beam charged particle system, the inspection system also includes a stage 9, which can be used to mount the object 7 to be inspected, such as a fabricated chip. The stage 9 can also include a detector 8, which is used to detect secondary charged particles generated by the multi-beam charged particles from the object 7 to be inspected, so as to generate a signal corresponding to the secondary charged particles. It can be understood that the electron beam generated by the multi-beam charged particle system is focused on the wafer to form an electron beam spot on the wafer. The detector 8 collects the secondary electrons and backscattered electrons generated on the wafer surface to obtain the morphological information of the wafer surface.

[0247] It should be noted that, in Figure 43 The diagram illustrates that the secondary charged particles generated by the object 7 to be inspected will be reflected into the detector 8, without limiting the transmission path of the secondary charged particles.

[0248] exist Figure 43 In the inspection system shown, since the first electrostatic lens 101A and the second electrostatic lens 102A can correct the defocus distance, the charged particle beams passing through the first electrostatic lens 101A and the second electrostatic lens 102A can both be focused on the chip to be inspected. Compared with the existing multi-beam charged particle systems with large defocus differences, this system can ensure that the charged particle beams are all focused on the chip to be inspected, rather than partially focused on the chip and partially focused above it. Therefore, using the inspection system provided in this application, the obtained chip morphology information will be clearer and the acquisition efficiency will be faster.

[0249] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0250] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An electrostatic lens, characterized in that, include: First electrode layer; A second electrode layer is formed by stacking the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer are insulated from each other. The first electrode layer includes: a first portion of the first electrode layer and a second portion of the first electrode layer; The second electrode layer includes: a first portion of the second electrode layer and a second portion of the second electrode layer; The first portion of the first electrode layer and the first portion of the second electrode layer are arranged along the stacking direction, and the second portion of the first electrode layer and the second portion of the second electrode layer are arranged along the stacking direction. The first portion of the second electrode layer protrudes towards the first electrode layer relative to the second portion of the second electrode layer. The first portion of the first electrode layer protrudes away from the second portion of the first electrode layer in a direction away from the second electrode layer. A first hole is formed in the first part of the first electrode layer, which penetrates the first electrode layer along the stacking direction; and a second hole is formed in the second part of the first electrode layer, which penetrates the first electrode layer along the stacking direction. A third hole communicating with the first hole is provided in the first part of the second electrode layer, and a fourth hole communicating with the second hole is provided in the second part of the second electrode layer.

2. The electrostatic lens according to claim 1, characterized in that, Along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, and the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

3. The electrostatic lens according to claim 1, characterized in that, The first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

4. The electrostatic lens according to claim 1, characterized in that, The first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

5. The electrostatic lens according to any one of claims 1 to 4, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

6. The electrostatic lens according to any one of claims 1 to 4, characterized in that, The diameter of the first hole is equal to the diameter of the third hole; And / or, The diameter of the second hole is the same as the diameter of the fourth hole.

7. The electrostatic lens according to any one of claims 1 to 4, characterized in that, Either the first portion of the first electrode layer or the second portion of the first electrode layer is a planar structure perpendicular to the stacking direction, and the junction of the first portion of the first electrode layer and the second portion of the first electrode layer has a step.

8. The electrostatic lens according to any one of claims 1 to 4, characterized in that, The electrostatic lens also includes: A dielectric layer, the first electrode layer, the dielectric layer, and the second electrode layer are stacked sequentially along the stacking direction; The dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole.

9. The electrostatic lens according to any one of claims 1 to 4, characterized in that, The electrostatic lens also includes: The first power supply terminal is electrically connected to the first electrode layer; The second power terminal is electrically connected to the second electrode layer.

10. A multi-beam charged particle system, characterized in that, include: Particle source, used to generate charged particles; The electrostatic lens as described in any one of claims 1 to 9; The electrostatic lens is arranged in the beam path of the charged particles.

11. The multi-beam charged particle system according to claim 10, characterized in that, The multi-beam charged particle system is a multi-beam charged particle inspection system, which further includes: A platform is used to mount the object to be inspected, and the multi-beam charged particles after passing through the electrostatic lens are focused onto the object to be inspected. A detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

12. The multi-beam charged particle system according to claim 10, characterized in that, The multi-beam charged particle system is a multi-beam charged particle mapping system, which further includes: A platform is used to mount the object to be etched. Multi-beam charged particles, after passing through the electrostatic lens, are focused onto the object to be etched, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be etched.

13. A method for inspecting a substrate using multi-beam charged particles, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the substrate. Detect secondary charged particles generated by the multi-beam charged particles from the substrate to generate a signal corresponding to the secondary charged particles; The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion, and the second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion. The method of focusing the multi-beam charged particles onto the substrate using an electrostatic lens arranged in the beam path of the charged particles includes: The first charged particle beam in the multi-beam charged particle array is focused onto the substrate by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the substrate by passing through the connected second and fourth holes.

14. The method of inspection according to claim 13, characterized in that, The electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer and the second power terminal is electrically connected to the second electrode layer; The method of focusing the multi-beam charged particles onto the substrate using an electrostatic lens arranged in the beam path of the charged particles further includes: A first voltage is applied to the first electrode layer through the first power terminal; A second voltage, which is not equal to the first voltage, is applied to the second electrode layer through the second power terminal.

15. The method of inspection according to claim 13 or 14, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

16. The method of inspection according to claim 13 or 14, characterized in that, The first part of the second electrode layer protrudes towards the first electrode layer relative to the second part of the second electrode layer. Along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, and the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

17. The method of inspection according to claim 13 or 14, characterized in that, The first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

18. The method of inspection according to claim 13 or 14, characterized in that, The first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

19. A method for engraving on an object coated with an anti-corrosion agent, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the object to be etched, which is coated with an anti-corrosion agent, so as to form a particle beam spot on the object to be etched. The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion, and the second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion. The method of focusing multiple beams of charged particles onto the object to be patterned using an electrostatic lens arranged in the beam path of the charged particles includes: The first charged particle beam in the multi-beam charged particle array is focused onto the object to be patterned by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the object to be patterned by passing it through the connected second and fourth holes.

20. The engraving method according to claim 19, characterized in that, The electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer and the second power terminal is electrically connected to the second electrode layer; The method of focusing the multi-beam charged particles onto the object to be patterned using an electrostatic lens arranged in the beam path of the charged particles also includes: A first voltage is applied to the first electrode layer through the first power terminal; A second voltage, which is not equal to the first voltage, is applied to the second electrode layer through the second power terminal.

21. The engraving method according to claim 19 or 20, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

22. The engraving method according to claim 19 or 20, characterized in that, The first part of the second electrode layer protrudes towards the first electrode layer relative to the second part of the second electrode layer. Along the stacking direction, the distance between the port of the first hole near the third hole and the port of the third hole near the first hole is d1, and the distance between the port of the second hole near the fourth hole and the port of the fourth hole near the second hole is d2, and d1=d2.

23. The engraving method according to claim 19 or 20, characterized in that, The first portion of the second electrode layer protrudes away from the first electrode layer relative to the second portion of the second electrode layer.

24. The engraving method according to claim 19 or 20, characterized in that, The first portion of the second electrode layer and the second portion of the second electrode layer are located in a first plane, and the first plane is perpendicular to the stacking direction.

25. An electrostatic lens, characterized in that, include: First electrode layer; A second electrode layer is formed by stacking the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer are insulated from each other. The first electrode layer includes: a first portion of the first electrode layer and a second portion of the first electrode layer, wherein the first portion of the first electrode layer and the second portion of the first electrode layer are insulated from each other; The second electrode layer includes: a first portion of the second electrode layer and a second portion of the second electrode layer, wherein the first portion of the second electrode layer and the second portion of the second electrode layer are insulated from each other; The first portion of the first electrode layer and the first portion of the second electrode layer are arranged along the stacking direction, and the second portion of the first electrode layer and the second portion of the second electrode layer are arranged along the stacking direction. The first portion of the second electrode layer protrudes towards the first electrode layer relative to the second portion of the second electrode layer, and the first portion of the first electrode layer protrudes away from the second electrode layer relative to the second portion of the first electrode layer. A first hole is formed in the first part of the first electrode layer, which penetrates the first electrode layer along the stacking direction; and a second hole is formed in the second part of the first electrode layer, which penetrates the first electrode layer along the stacking direction. A third hole communicating with the first hole is formed in the first part of the second electrode layer, and a fourth hole communicating with the second hole is formed in the second part of the second electrode layer. The electrostatic lens also includes: The first power terminal is electrically connected to the first portion of the first electrode layer; The second power terminal is electrically connected to the second part of the first electrode layer; The third power terminal is electrically connected to the first part of the second electrode layer; The fourth power terminal is electrically connected to the second part of the second electrode layer.

26. The electrostatic lens according to claim 25, characterized in that, The first portion of the first electrode layer and the second portion of the first electrode layer are located in a first plane, and the first portion of the second electrode layer and the second portion of the second electrode layer are located in a second plane, and both the first plane and the second plane are perpendicular to the stacking direction.

27. The electrostatic lens according to claim 25 or 26, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

28. The electrostatic lens according to claim 25 or 26, characterized in that, The diameter of the first hole is equal to the diameter of the third hole; And / or, The diameter of the second hole is the same as the diameter of the fourth hole.

29. The electrostatic lens according to claim 25 or 26, characterized in that, The electrostatic lens also includes: A first dielectric layer, a first electrode layer, a first dielectric layer, and a second electrode layer are stacked sequentially along the stacking direction; The first dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole; The second dielectric layer separates the first portion of the first electrode layer from the second portion of the first electrode layer, and the second portion of the second electrode layer from the first portion of the second electrode layer.

30. A multi-beam charged particle system, characterized in that, include: Particle source, used to generate charged particles; The electrostatic lens as described in any one of claims 26 to 29; The electrostatic lens is arranged in the beam path of the charged particles.

31. The multi-beam charged particle system according to claim 30, characterized in that, The multi-beam charged particle system is a multi-beam charged particle inspection system, which further includes: A platform is used to mount the object to be inspected, and the multi-beam charged particles after passing through the electrostatic lens are focused onto the object to be inspected. A detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

32. The multi-beam charged particle system according to claim 30, characterized in that, The multi-beam charged particle system is a multi-beam charged particle mapping system, which further includes: A platform is used to mount the object to be etched. Multi-beam charged particles, after passing through the electrostatic lens, are focused onto the object to be etched, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be etched.

33. A method for inspecting a substrate using multi-beam charged particles, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the substrate. Detect secondary charged particles generated by the multi-beam charged particles from the substrate to generate a signal corresponding to the secondary charged particles; The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion that are insulated from each other. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion that are insulated from each other. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion, and the first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion. The method of focusing the multi-beam charged particles onto the substrate using an electrostatic lens arranged in the beam path of the charged particles includes: Different voltages are applied to the first part of the first electrode layer, the second part of the first electrode layer, the first part of the second electrode layer, and the second part of the second electrode layer. The first charged particle beam in the multi-beam charged particle array is focused onto the substrate by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the substrate by passing through the connected second and fourth holes.

34. The method of inspection according to claim 33, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

35. A method for engraving on an object coated with an anti-corrosion agent, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the object to be etched, which is coated with an anti-corrosion agent, so as to form a particle beam spot on the object. The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion that are insulated from each other. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion that are insulated from each other. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion, and the first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion. The method of focusing multiple beams of charged particles onto the object to be patterned using an electrostatic lens arranged in the beam path of the charged particles includes: Different voltages are applied to the first part of the first electrode layer, the second part of the first electrode layer, the first part of the second electrode layer, and the second part of the second electrode layer. The first charged particle beam in the multi-beam charged particle array is focused onto the object to be patterned by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the object to be patterned by passing it through the connected second and fourth holes.

36. The engraving method according to claim 35, characterized in that, The diameter of the first hole is not equal to the diameter of the second hole.

37. An electrostatic lens, characterized in that, include: First electrode layer; A second electrode layer is formed by stacking the first electrode layer and the second electrode layer, and the first electrode layer and the second electrode layer are insulated from each other. The first electrode layer includes: a first portion of the first electrode layer and a second portion of the first electrode layer; The second electrode layer includes: a first portion of the second electrode layer and a second portion of the second electrode layer; The first portion of the first electrode layer and the first portion of the second electrode layer are arranged along the stacking direction, and the second portion of the first electrode layer and the second portion of the second electrode layer are arranged along the stacking direction. The first portion of the second electrode layer protrudes towards the first electrode layer relative to the second portion of the second electrode layer, and the first portion of the first electrode layer protrudes away from the second electrode layer relative to the second portion of the first electrode layer. A first hole is formed in the first part of the first electrode layer, which penetrates the first electrode layer along the stacking direction; and a second hole is formed in the second part of the first electrode layer, which penetrates the first electrode layer along the stacking direction. A third hole communicating with the first hole is formed in the first part of the second electrode layer, and a fourth hole communicating with the second hole is formed in the second part of the second electrode layer. The diameter of the first hole is not equal to the diameter of the second hole.

38. The electrostatic lens according to claim 37, characterized in that, The diameter of the first hole is equal to the diameter of the third hole; And / or, The diameter of the second hole is the same as the diameter of the fourth hole.

39. The electrostatic lens according to claim 37 or 38, characterized in that, The first portion of the first electrode layer and the second portion of the first electrode layer are located in a first plane, and the first portion of the second electrode layer and the second portion of the second electrode layer are located in a second plane, and both the first plane and the second plane are perpendicular to the stacking direction.

40. The electrostatic lens according to claim 37 or 38, characterized in that, The electrostatic lens also includes: A dielectric layer, the first electrode layer, the dielectric layer, and the second electrode layer are stacked sequentially along the stacking direction; The dielectric layer has a hole connecting the first hole and the third hole, and a hole connecting the second hole and the fourth hole.

41. The electrostatic lens according to claim 37 or 38, characterized in that, The electrostatic lens also includes: The first power supply terminal is electrically connected to the first electrode layer; The second power terminal is electrically connected to the second electrode layer.

42. A multi-beam charged particle system, characterized in that, include: Particle source, used to generate charged particles; The electrostatic lens as described in any one of claims 37 to 41; The electrostatic lens is arranged in the beam path of the charged particles.

43. The multi-beam charged particle system according to claim 42, characterized in that, The multi-beam charged particle system is a multi-beam charged particle inspection system, which further includes: A platform is used to mount the object to be inspected, and the multi-beam charged particles after passing through the electrostatic lens are focused onto the object to be inspected. A detector is used to detect secondary charged particles generated by the multi-beam charged particles from the object to be inspected, so as to generate a signal corresponding to the secondary charged particles.

44. The multi-beam charged particle system according to claim 42, characterized in that, The multi-beam charged particle system is a multi-beam charged particle mapping system, which further includes: A platform is used to mount the object to be etched. Multi-beam charged particles, after passing through the electrostatic lens, are focused onto the object to be etched, which is coated with an anti-corrosion agent, to form a particle beam spot on the object to be etched.

45. A method for inspecting a substrate using multi-beam charged particles, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the substrate. Detect secondary charged particles generated by the multi-beam charged particles from the substrate to generate a signal corresponding to the secondary charged particles; The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion that are insulated from each other. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion that are insulated from each other. The second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion, and the first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The diameter of the first hole is not equal to the diameter of the second hole. The method of focusing the multi-beam charged particles onto the substrate using an electrostatic lens arranged in the beam path of the charged particles includes: The first charged particle beam in the multi-beam charged particle array is focused onto the substrate by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the substrate by passing through the connected second and fourth holes.

46. ​​The method of inspection according to claim 45, characterized in that, The electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer and the second power terminal is electrically connected to the second electrode layer; The method of focusing the multi-beam charged particles onto the substrate using an electrostatic lens arranged in the beam path of the charged particles further includes: A first voltage is applied to the first electrode layer through the first power terminal; A second voltage, which is not equal to the first voltage, is applied to the second electrode layer through the second power terminal.

47. A method for engraving on an object coated with an anti-corrosion agent, characterized in that, include: Using a particle source to generate charged particles; An electrostatic lens arranged in the beam path of the charged particles is used to focus multiple beams of charged particles onto the object to be etched, which is coated with an anti-corrosion agent, so as to form a particle beam spot on the object. The electrostatic lens includes a stacked and insulated first electrode layer and a second electrode layer. The first electrode layer includes a first electrode layer first portion and a first electrode layer second portion that are insulated from each other. The second electrode layer includes a second electrode layer first portion and a second electrode layer second portion that are insulated from each other. The second electrode layer first portion protrudes towards the first electrode layer relative to the second electrode layer second portion, and the first electrode layer first portion protrudes away from the second electrode layer relative to the first electrode layer second portion. The first electrode layer first portion has a first hole, the first electrode layer second portion has a second hole, the second electrode layer first portion has a third hole communicating with the first hole, and the second electrode layer second portion has a fourth hole communicating with the second hole. The diameter of the first hole is not equal to the diameter of the second hole. The step of focusing the multi-beam charged particles onto the object to be patterned using an electrostatic lens arranged in the beam path of the charged particles includes: The first charged particle beam in the multi-beam charged particle array is focused onto the object to be patterned by passing through the first and third interconnected holes. The second charged particle beam from the multi-splitter charged particles is focused onto the object to be patterned by passing it through the connected second and fourth holes.

48. The engraving method according to claim 47, characterized in that, The electrostatic lens further includes: a first power terminal and a second power terminal, wherein the first power terminal is electrically connected to the first electrode layer and the second power terminal is electrically connected to the second electrode layer; The method of focusing the multi-beam charged particles onto the object to be patterned using an electrostatic lens arranged in the beam path of the charged particles also includes: A first voltage is applied to the first electrode layer through the first power terminal; A second voltage, which is not equal to the first voltage, is applied to the second electrode layer through the second power terminal.

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