Focusing imaging device and focusing imaging system

Abstract

According to the focusing imaging device and the focusing imaging system provided by the invention, 3D imaging is realized by arranging the focusing imaging lens group, and the electron beam in the uplink path is not deflected and is not required to be subjected to reverse polarization compensation, so that the drop point energy of the downlink electron beam on the surface of a sample can be adjusted in a large range, and the requirement on working parameter switching can be met. The focusing imaging device can comprise an electron source, an intermediate lens group and a focusing imaging lens group. The electron source can be used for outputting a first downlink electron beam to the middle lens group. The middle lens group can be used for controlling the drop point position of the first downlink electron beam on the sample by scanning the first downlink electron beam. And the focusing imaging lens group can be used for focusing the first downlink electron beam to the surface of the sample according to the drop point position and imaging according to the uplink electron beam generated on the surface of the sample.

Description

Technical Field

[0001] The present application relates to the technical field of electron beam imaging, and more particularly, to a focusing imaging device and a focusing imaging system based on multiple electron beams. Background Art

[0002] In semiconductor and biological applications, it is often necessary to image samples such as wafers and biological tissues over a large area using an imaging device, which places higher demands on the throughput of the imaging device. The imaging device provided by the related art uses multi-electron beam technology to divide the electron beam into multiple parallel-transmitted sub-electron beams, which can image different areas of the sample, thereby improving the throughput of the imaging device while ensuring resolution. However, the imaging device provided by the related art uses a method that separates the downlink path for transmitting the downlink electron beam and the uplink path for collecting the uplink electron beam to achieve electron beam collection and imaging. Although the electron beam collection efficiency is high, the downlink and uplink paths are too long and complex, resulting in the loss of the electron beam's emission direction in space, making 3D imaging impossible. At the same time, since the electron beam in the uplink path will undergo unnecessary deflection through the scanner, reverse bias compensation is required. However, due to the complexity of reverse bias compensation, when the energy of the downlink electron beam's landing point on the sample surface is adjusted over a large range, the collection efficiency of the uplink path is difficult to guarantee. Therefore, the requirements for switching the working parameters of the imaging device cannot be met. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings, the present application provides a focusing imaging device and a focusing imaging system, which realize 3D imaging by setting a focusing imaging lens group. In the present application, the electron beam (i.e., the upward electron beam) in the upward path (i.e., the collection path) will not be deflected, and no reverse bias compensation is required. Therefore, the landing energy of the downward electron beam on the sample surface can be adjusted over a large range, which can meet the requirements for switching working parameters.

[0004] In a first aspect, the present application provides a focusing imaging device, which may include an electron source, an intermediate lens group, and a focusing imaging lens group.

[0005] The electron source can be used to output a first downward electron beam to the intermediate mirror group.

[0006] The intermediate mirror assembly can be used to control the landing position of the first downward electron beam on the sample by scanning the first downward electron beam.

[0007] The focusing and imaging lens assembly can be used to focus the first downward electron beam onto the surface of the sample based on the landing point, and to image the upward electron beam generated on the sample surface. As can be seen, the present application combines the downward path (i.e., the transmission path of the first downward electron beam) and the upward path through the focusing and imaging lens assembly.

[0008] In the focusing imaging device provided herein, the length and complexity of the upward path are shortened by the focusing imaging lens assembly, reducing the complexity of the upward path. This allows the upward electron beam to carry the spatial direction information of the first downward electron beam, thus achieving 3D imaging. Furthermore, the upward electron beam passes only through the focusing imaging lens assembly, not the intermediate lens assembly. Therefore, the upward electron beam is not deflected, eliminating the need for reverse deflection compensation. Therefore, the energy of the downward electron beam at the sample surface can be adjusted over a wide range, meeting the requirements for switching operating parameters.

[0009] In a possible implementation, the focusing imaging lens assembly may include an electron detector and a first electron lens that are stacked.

[0010] The electron detector may include a first chip, the first electron lens may include a plurality of second chips, and the first chip and the plurality of second chips may be stacked.

[0011] Furthermore, the first chip may be provided with a plurality of first through holes, and each of the plurality of second chips may be provided with a plurality of second through holes, and the plurality of second through holes may correspond one-to-one to the plurality of first through holes.

[0012] Exemplarily, the electron detector may be configured to: split a first downstream electron beam into a plurality of second downstream electron beams through a plurality of first through holes.

[0013] The first electron lens can be used to focus the plurality of second downward electron beams onto the surface of the sample through the plurality of second through holes. Alternatively, the first electron lens can be used to collect the upward electron beam generated on the surface of the sample.

[0014] The electron detector can also be used to detect the upward electron beam through the multiple first through holes to perform imaging.

[0015] As can be seen, the focusing imaging device provided by the present application can achieve focusing of multiple second downlink electron beams and collection of the uplink electron beam by providing a first electron lens, while simultaneously detecting the uplink electron beam through an electron detector, thereby achieving imaging. In other words, the focusing imaging device provided by the present application can achieve both focusing and imaging.

[0016] In another possible implementation, the electron detector may be grounded, the sample may receive a first voltage, and the first electron lens may receive a second voltage. The first voltage may have a different value than the second voltage.

[0017] The first electron lens can be used to focus the plurality of second downward electron beams onto the surface of the sample according to an electric field formed by a voltage difference between the first voltage and the second voltage. Alternatively, the first electron lens can be used to collect the upward electron beam according to the electric field.

[0018] It can be seen that the present application can achieve the landing energy of multiple second downward electron beams on the sample surface by adjusting the respective voltage values of the first voltage and the second voltage, thereby meeting the requirements for switching of working parameters.

[0019] In some possible implementations, the intermediate mirror assembly may include a deflector, a blocking assembly, and a scanner that are stacked.

[0020] The deflector may include a plurality of third through holes, the blocking assembly may include a plurality of fourth through holes, and the scanner may include a plurality of fifth through holes. The plurality of third through holes, the plurality of fourth through holes, and the plurality of fifth through holes may correspond to each other.

[0021] The deflector can be used to adjust the angle of the first downstream electron beam through the plurality of third through holes and transmit the first downstream electron beam to the scanner through the plurality of fourth through holes.

[0022] The scanner can be used to: scan the first downward electron beam after the angle is adjusted through multiple fifth through holes, and control the landing position of the first downward electron beam after the angle is adjusted on the sample.

[0023] For example, the deflector may be a chip, etc. The blocking assembly may be a silicon wafer or a metal sheet, etc. The scanner may include multiple stacked third chips or multiple stacked metal multipoles. Of course, the deflector, blocking assembly, and scanner may also be of other types, which are not limited in this application.

[0024] Furthermore, the intermediate lens group may also include a beam splitter, an astigmatism corrector and a second electron lens.

[0025] The beam splitter may be located between the electron source and the deflector, and may be provided with a plurality of sixth through holes. The beam splitter may split the first downward electron beam through the plurality of sixth through holes.

[0026] The astigmatism corrector and the second electron lens can both be located between the deflector and the blocking assembly. The astigmatism corrector can be provided with a plurality of seventh through holes, and the second electron lens can be provided with a plurality of eighth through holes. The astigmatism corrector can correct the astigmatism of the angle-adjusted first downstream electron beam through the plurality of seventh through holes and transmit the corrected beam to the second electron lens. The second electron lens can focus the plurality of first downstream electron beams after astigmatism correction through the plurality of eighth through holes and transmit the corrected beam to the scanner through the plurality of fourth through holes.

[0027] Among them, the plurality of sixth through holes, the plurality of seventh through holes and the plurality of eighth through holes correspond to each other one by one.

[0028] Optionally, the beam splitter can be a silicon chip or a metal chip, etc. The astigmatism corrector and the second electron lens can both be chips, etc. Of course, the beam splitter, astigmatism corrector and the second electron lens can also be of other types, which are not limited in this application.

[0029] In some other possible implementations, the electron source may include an electron emitter and a third electron lens, wherein the third electron lens may be single-stage or multi-stage.

[0030] The electron emitter can be used to emit a third downward electron beam to a third electron lens.

[0031] The third electron lens can be used to collimate the third downstream electron beam to obtain the first downstream electron beam. It can be seen that the first downstream electron beam can be the third downstream electron beam after the collimation process.

[0032] Of course, in addition to collimating the third downstream electron beam, the third electron lens can also adjust the area and beam current density of the third downstream electron beam.

[0033] For example, the third electron lens may be a metal ring, a metal sheet, a magnetic coil, etc. Of course, the third electron lens may also be in other forms, which is not limited in this application.

[0034] In a second aspect, the present application provides a focusing imaging system, which may include a machine platform and the focusing imaging device provided by the first aspect and its possible implementations. The focusing imaging device may be arranged on the machine platform.

[0035] It should be understood that the second aspect of this application is consistent with the technical solution of the first aspect of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar, which will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 is a schematic structural diagram of a focusing imaging device in an embodiment of the present application;

[0038] Figure 2 is a schematic structural diagram of an electronic detector in an embodiment of the present application;

[0039] Figure 3 is a schematic structural diagram of the first electron lens in an embodiment of the present application;

[0040] Figure 4a is another schematic structural diagram of the first electron lens in an embodiment of the present application;

[0041] Figure 4bis another schematic structural diagram of the first electron lens in an embodiment of the present application;

[0042] Figure 4c is another schematic structural diagram of the first electron lens in an embodiment of the present application;

[0043] Figure 5a A schematic diagram of a collection efficiency state of a focusing imaging device in an embodiment of the present application;

[0044] Figure 5b This is another schematic diagram of a collection efficiency state of the focusing imaging device in an embodiment of the present application;

[0045] Figure 5c This is a schematic diagram of another state of collection efficiency of the focusing imaging device in an embodiment of the present application;

[0046] Figure 6a Schematic diagram of an upward electron beam emitted from a sample with a flat surface in an embodiment of the present application;

[0047] Figure 6b Schematic diagram of an upward electron beam emitted from a sample with an inclined surface in an embodiment of the present application;

[0048] Figure 7a A schematic diagram of a 2D focusing imaging principle of a focusing imaging device in an embodiment of the present application;

[0049] Figure 7b A schematic diagram of a 3D focusing imaging principle of a focusing imaging device in an embodiment of the present application;

[0050] Figure 7c This is another schematic diagram of a 3D focusing imaging principle of the focusing imaging device in an embodiment of the present application;

[0051] Figure 8a A spatial distribution diagram of an uplink single beamlet detected by the detection surface of the electron detector in the 3D imaging mode in an embodiment of the present application;

[0052] Figure 8b Another spatial distribution diagram of the uplink single beamlet detected by the detection surface of the electron detector in the 3D imaging mode in the embodiment of the present application;

[0053] Figure 9 A spatial distribution diagram of the upward electron beam in the 2D imaging mode in an embodiment of the present application;

[0054] Figure 10 is a schematic structural diagram of a focusing imaging device in an embodiment of the present application;

[0055] Figure 11 A spatial distribution diagram of the upward electron beam in the 3D imaging mode in an embodiment of the present application;

[0056] Figure 12a A schematic diagram of a switch for a downward electron beam obtained by an electron detector in an embodiment of the present application;

[0057] Figure 12b Another switching schematic diagram of a downward electron beam obtained by an electron detector in an embodiment of the present application;

[0058] Figure 13 A schematic structural diagram of a sample in an embodiment of the present application;

[0059] Figure 14a A schematic diagram of imaging a sample using the focusing imaging device provided in an embodiment of the present application;

[0060] Figure 14b This is another schematic diagram of imaging a sample using the focusing imaging device provided in an embodiment of the present application;

[0061] Figure 14c This is another schematic diagram of imaging a sample using the focusing imaging device provided in an embodiment of the present application;

[0062] Figure 15 This is a schematic structural diagram of a focusing imaging device in an embodiment of the present application. DETAILED DESCRIPTION

[0063] The technical solution in this application will be described below with reference to the accompanying drawings.

[0064] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0065] The terms "first," "second," and the like in the description, embodiments, claims, and drawings of this application are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions, such as, for example, inclusion of a series of steps or units. A method, system, product, or apparatus is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0066] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0067] In application scenarios such as semiconductors and biology, it is usually necessary to use an imaging device to image samples such as wafers and biological tissues with a large area, so higher requirements are placed on the flux of the imaging device. The imaging device provided by the related art adopts multi-electron beam technology to divide the electron beam into multiple sub-electron beams transmitted in parallel, which can image different areas of the sample, thereby improving the flux of the imaging device while ensuring the resolution. However, the imaging device provided by the related art adopts a method of separating the downlink path and the uplink path to realize the collection and imaging of the electron beam. Although the collection efficiency of the electron beam is high, the downlink path and the uplink path are too long and complicated, resulting in the loss of the electron beam in the spatial emission direction, and 3D imaging cannot be achieved. At the same time, since the electron beam in the uplink path will undergo unnecessary deflection through the scanner, reverse bias compensation is required. However, due to the complexity of reverse bias compensation, it is difficult to adjust the landing energy of the electron beam in the downlink path on the sample surface over a large range. Therefore, the requirements for switching the working parameters of the imaging device cannot be met.

[0068] In order to overcome the above shortcomings, the present invention provides a focusing imaging device. Figure 1 shown. Figure 1 The focusing imaging device 100 may include an electron source 1 , an intermediate lens group 2 and a focusing imaging lens group 3 .

[0069] The electron source 1 can be used to: output the first downlink electron beam (can be EB down1 Indicates) to the middle lens group 2.

[0070] The intermediate mirror group 2 can be used to scan the first downstream electron beam EB down1 Control EB down1 The landing point on the sample S. In the embodiment of the present application, the sample S may be a wafer.

[0071] The focusing imaging lens group 3 can be used to: down1 Focusing on the surface of the sample S, the upward electron beam (EB up It can be seen that the embodiment of the present application can use the focusing imaging lens group 3 to focus the downlink path (ie EB down1 transmission path) and the uplink path (ie EB up transmission paths).

[0072] In the focusing imaging device 100 provided in the embodiment of the present application, the length of the uplink path (i.e., the collection path of the uplink electron beam) can be shortened by the focusing imaging lens group 3, and the complexity of the uplink path can be reduced, so that the EB up Carrying EB down1 3D imaging can be achieved by using the spatial direction information of up It will only pass through the focusing and imaging lens group 3, but not the intermediate lens group 2, so EB up It will not be deflected and does not require back-bias compensation, so the EB can be adjusted over a wide range down1 The landing energy on the surface of sample S can meet the requirements for switching working parameters.

[0073] In some embodiments, reference Figure 1 The focusing imaging lens group 3 may include an electron detector 31 and a first electron lens 32 which are stacked.

[0074] The electron detector 31 may include a first chip, and the first electron lens 32 may include a plurality of second chips. The first chip and the plurality of second chips may be stacked.

[0075] That is, the electron detector 31 can be implemented by using a first chip, and the first electron lens 32 can be implemented by using a plurality of second chips.

[0076] In the embodiment of the present application, the first electronic lens 32 may include three second chips, such as Figure 1 Of course, the electron detector 31 and the first electron lens 32 may also be of other types, which are not limited in the embodiment of the present application.

[0077] Furthermore, if Figure 2 As shown, the electron detector 31 (ie, the first chip) may include 36 (ie, multiple) active areas 311 and be provided with 36 (ie, multiple) first through holes H1. In the embodiment of the present application, the 36 first through holes H1 are evenly arranged. Figure 3As shown, the first electron lens 32 (i.e., each second chip) can be provided with 36 (i.e., a plurality of) second through holes H2. In the embodiment of the present application, the 36 second through holes H2 are evenly arranged. It is conceivable that the 36 second through holes H2 can correspond one-to-one to the 36 first through holes H1.

[0078] Optionally, the first electron lens 32 may include three second chips 321, such as Figure 4a Alternatively, the first electron lens 32 may include four second chips 321, as shown in FIG. Figure 4b Of course, the first electron lens 32 may also include five second chips 321, such as Figure 4c Of course, the first electronic lens 32 may also include more second chips, which may be configured according to specific application scenarios. The embodiment of the present application does not limit the number of second chips.

[0079] For example, the electron detector 31 can be used to: down1 Divided into multiple second downward electron beams (can be used EB down2 express).

[0080] The first electron lens 32 can be used to: transmit a plurality of EBs through a plurality of second through holes H2 down2 Focused on the surface of the sample S. Alternatively, the first electron lens 32 can be used to collect the EB generated on the surface of the sample S. up Relatively speaking, the first electron lens 32 is closer to the sample S, so the first electron lens 32 can also be called an objective lens.

[0081] The electron detector 31 can also be used to detect EB through the plurality of first through holes H1 up Perform imaging.

[0082] It can be seen that the focusing imaging device 100 provided in the embodiment of the present application can realize multiple EB by setting the first electron lens 32. down2 Focus and EB up The EB is collected and detected by the electron detector 31. up , thereby achieving imaging. That is, the focusing imaging device 100 provided in the embodiment of the present application can not only achieve focusing, but also achieve imaging. At the same time, the uplink path can be shortened to a few millimeters through the electron detector 31 and the first electron lens 32.

[0083] In another possible implementation, the electron detector 31 can be grounded. The sample S can be configured to receive a first voltage (which can be represented by V1). The first electron lens 32 can be configured to receive a second voltage (which can be represented by V2). The voltage value of the first voltage V1 can be different from the voltage value of the second voltage V2.

[0084] The first electron lens 32 can be used to: down2 Focused on the surface of the sample S. Alternatively, the first electron lens 32 can be used to collect EB according to the electric field up .

[0085] It can be seen that the embodiment of the present application can realize multiple EB by adjusting the voltage values of the first voltage V1 and the second voltage V2. down2 The landing energy on the surface of sample S can meet the requirements for switching working parameters.

[0086] Optionally, the detection surface of the electron detector 31 may face the sample S. At least one of the first voltage V1, the second voltage V2, and the distance between the first electron lens 32 and the sample S is adjusted, EB up The spatial distribution of the detection surface of the electron detector 31 can be adjusted by the second voltage V2 received by the first electron lens 32. up The beam spot size can be comparable to the size of the active area 311 (can be the same, or within a preset deviation range), so as to form the following Figure 5a The better collection efficiency state is shown.

[0087] Of course, if EB up The spatial distribution of the detection surface of the electron detector 31 is too concentrated, EB up Most of the electron beams will pass through the first through hole H1 of the electron detector 31, resulting in the electrons being unable to be effectively collected, that is, forming Figure 5b If the upward electron beam is too dispersed in the space of the detection surface of the electron detector 31, EB up Most of the electron beams will be blocked by the first electron lens 32, resulting in a waste of electrons, forming the following Figure 5c The high crosstalk state shown (i.e., the electrons in the upward electron beam reach the detection area of other nearby pixels, forming a crosstalk signal).

[0088] Crosstalk of the upward electron beam may be suppressed by adjusting at least one of the first voltage V1, the second voltage V2, and the distance between the first electron lens 32 and the sample S. Since the spatial distribution of secondary electrons generated on the surface of the sample S may follow a cosine distribution, the direction of the maximum value thereof is perpendicular to the local tangent direction of the sample S.

[0089] In one example, the surface of the sample S is flat, then EB up The electrons are emitted upward along the maximum direction, such as Figure 6a shown.

[0090] In another example, the surface of the sample S has a slope (or ups and downs), and the EB generated on the surface of the sample S up There will be spatial asymmetry, such as Figure 6b shown.

[0091] The focusing imaging device 100 provided in the embodiment of the present application can have a 2D imaging mode and a 3D imaging mode, and the uplink path can have a low crosstalk mode and a high crosstalk mode.

[0092] In one example, the focusing imaging device 100 is in 2D imaging mode, the uplink path is configured as a low crosstalk mode, and the electron detector 31 collects the uplink electron beam to obtain the following Figure 7a The 2D focusing imaging principle diagram of the focusing imaging device 100 is shown in FIG. Figure 7a It can be seen that the crosstalk signal C1 and the crosstalk signal C2 can be symmetrical.

[0093] In another example, the focusing imaging device 100 is in 3D imaging mode, the surface of the sample S is flat, the uplink path is configured as a high crosstalk mode, and the electron detector 31 collects EB up , and get Figure 7b The 3D focusing imaging principle diagram of the focusing imaging device 100 is shown in FIG. Figure 7b It can be seen that the crosstalk signal C1 and the crosstalk signal C2 can be symmetrical.

[0094] In another example, the focusing imaging device 100 is in 3D imaging mode, the surface of the sample S is an inclined surface, the uplink path is configured as a high crosstalk mode, and the electron detector 31 collects EB up , and get Figure 7c The 3D focusing imaging principle diagram of the focusing imaging device 100 is shown in FIG. Figure 7c It can be seen that the crosstalk signal is only C2, that is, the crosstalk signal can be asymmetric.

[0095] from Figures 7a to 7c It can be seen that EB in the embodiment of this application up The spatial orientation asymmetry information carried can be converted into spatial position distribution asymmetry information at the electron detector 31 and detected by the electron detector 31. At this time, the crosstalk signals collected by the pixels surrounding the downlink electron beam become asymmetric. Therefore, the difference in crosstalk intensity of the surrounding pixels can be used to infer the undulation direction of the surface of the sample S. At the same time, in 3D imaging mode, the crosstalk rate of the surrounding uplink electron beam can be increased by adjusting the first voltage V1, the second voltage V2, or the distance between the first electron lens 32 and the sample S, thereby improving the image signal-to-noise ratio of the surrounding uplink electron beam.

[0096] In some embodiments, the focusing imaging device 100 is in 3D imaging mode, and the surface of the sample S is flat.up The EB detected by the detection surface of the electron detector 31 is grouped in a 3×3 matrix. up The spatial distribution diagram of Figure 8a As shown. Figure 8a It can be seen that EB up Has spatial symmetry.

[0097] In some other embodiments, the focusing imaging device 100 is in a 3D imaging mode, and the surface of the sample S is an inclined surface. up The EB detected by the detection surface of the electron detector 31 is grouped in a 3×3 matrix. up The spatial distribution diagram of Figure 8b As shown. Figure 8b It can be seen that EB up The spatial distribution is obviously asymmetric.

[0098] For example, when the focusing imaging device 100 is in 2D imaging mode, refer to Figure 1 , EB down1 It is divided into 36 EBs by the electron detector 31 down2 ( Figure 1 Only 6 EB can be reflected in down2 ), 36 EB down2 The electron beams are collected by the electron detector 31 and then sent to the sample S through the first electron lens 32. up , we can get Figure 9 EB shown up The spatial distribution diagram of the electron detector 31. down2 One to one correspondence. Figure 9 It can be seen that the focusing imaging device 100 provided in the embodiment of the present application can operate in parallel with multiple downlink electron beams, thereby improving the flux while ensuring the resolution.

[0099] Of course, when the focusing imaging device 100 is in 3D imaging mode, the EB down1 Beam splitting. That is, EB down1 The electron detector 31 is divided into multiple groups. Within each group, only the central downward electron beam descends, while the surrounding downward electron beams can be blocked by the electron detector 31, effectively switching the downward electron beams. Consequently, the electron detector 31 pixels corresponding to the surrounding downward electron beams only collect the crosstalk signal generated by the central downward electron beam, thereby achieving imaging based on the strength of the crosstalk signal.

[0100] In the embodiment of the present application, EB can be arranged in a 6×6 matrix form. down1 Group, refer to Figure 10 , EB down1 It is divided into 9 EBs by the electron detector 31down2 ( Figure 10 Only 3 EB can be reflected in down2 ), 9 EB down2 The electron beams are collected by the electron detector 31 and then sent to the sample S through the first electron lens 32. up , we can get Figure 11 EB shown up The spatial distribution diagram of the electron detector 31. down2 One to one correspondence.

[0101] Of course, in addition to EB in the form of a 3×3 matrix, down1 In the embodiment of the present application, the EB can also be grouped in a 5×5 or 7×7 matrix form. down1 Grouping, we get Figure 12a and Figure 12b The diagram shows a switching diagram of the downward electron beam obtained by the electron detector 31.

[0102] In some embodiments, the focusing imaging device 100 provided by the embodiment of the present application is used to Figure 13 The sample S shown was imaged. Figure 13 It can be seen that the sample S may have a groove G, which includes a first inclined surface G1, a bottom surface G2, and a second inclined surface G3. The other areas on the surface of the sample S except the groove G portion can be represented by S1 and S2, referring to Figure 13 .

[0103] The focusing imaging device 100 works in the 3D imaging mode and can obtain the following Figure 14a 、 Figure 14b and Figure 14c Schematic diagram of imaging of sample S shown in FIG. Figure 14a 、 Figure 14b and Figure 14c , the g1 region corresponds to the S1 region of the sample S, the g2 region corresponds to the S2 region of the sample S, the g3 region corresponds to the first inclined surface G1, the g4 region corresponds to the bottom surface G2, and the g5 region corresponds to the second inclined surface G3.

[0104] from Figure 14a 、 Figure 14b and Figure 14c It can be seen that the S1 area of sample S, the bottom surface G2 and the S2 area of sample S are all flat surfaces, and the corresponding g1 area, g4 area and g2 area have no difference in imaging grayscale values. Figure 14aIt can be seen that the imaging grayscale value of the g3 region corresponding to the first inclined surface G1 is significantly stronger than the imaging grayscale values of the g1 region, g4 region and g2 region, while the imaging grayscale value of the g5 region corresponding to the second inclined surface G3 is significantly weaker than the imaging grayscale values of the g1 region, g4 region and g2 region. Figure 14c It can be seen that the imaging grayscale value of the g3 region corresponding to the first inclined surface G1 is significantly weaker than the imaging grayscale values of the g1, g4, and g2 regions, while the imaging grayscale value of the g5 region corresponding to the second inclined surface G3 is significantly stronger than the imaging grayscale values of the g1, g4, and g2 regions. In other words, for inclined surfaces with different normals (which can be the first inclined surface G1 or the second inclined surface G3), the imaging grayscale values are significantly different. Figure 14b It can be seen that the imaging grayscale value of the g3 region corresponding to the first inclined surface G1 is comparable to the imaging grayscale value of the g5 region corresponding to the second inclined surface G3, and both are slightly weaker than the imaging grayscale values of the g1 region, the g4 region and the g2 region.

[0105] refer to Figure 1 and Figure 15 The intermediate mirror assembly 2 may include a deflector 21 , a blocking assembly 22 and a scanner 23 that are stacked.

[0106] The deflector 21 may include a plurality of third through holes, the blocking assembly 22 may include a plurality of fourth through holes, and the scanner 23 may include a plurality of fifth through holes. The plurality of third through holes, the plurality of fourth through holes, and the plurality of fifth through holes may correspond to each other.

[0107] It is conceivable that the plurality of first through holes, the plurality of second through holes, the plurality of third through holes, the plurality of fourth through holes, and the plurality of fifth through holes may all correspond one to one.

[0108] Furthermore, the deflector 21 can be used to adjust EB through a plurality of third through holes. down1 and transmitted to the scanner 23 through a plurality of fourth through holes.

[0109] The scanner 23 can be used to scan the EB after the angle adjustment through the plurality of fifth through holes. down1 , EB after control angle adjustment down1 The landing point position on sample S.

[0110] For example, the deflector 21 can be a chip, etc. The blocking assembly 22 can be a silicon wafer or a metal sheet, etc. The scanner 23 can include multiple stacked third chips or multiple stacked metal multipoles. In other words, the scanner can be implemented using a third chip or a metal multipoles.

[0111] Of course, the deflector 21 , the blocking assembly 22 and the scanner 23 may also be of other types, which is not limited in the embodiment of the present application.

[0112] Furthermore, as shown in FIG6 , the intermediate lens group 2 may further include a beam splitter 24 , an astigmatism corrector 25 and a second electron lens 26 .

[0113] The beam splitter 24 can be located between the electron source 1 and the deflector 21 and can be provided with a plurality of sixth through holes. The astigmatism corrector 25 and the second electron lens 26 can both be located between the deflector 21 and the blocking assembly 22. The astigmatism corrector 25 can be provided with a plurality of seventh through holes. The second electron lens 26 can be provided with a plurality of eighth through holes. The plurality of sixth through holes, the plurality of seventh through holes, and the plurality of eighth through holes correspond one to one.

[0114] It can be understood that the plurality of first through holes, the plurality of second through holes, the plurality of third through holes, the plurality of fourth through holes, the plurality of fifth through holes, the plurality of sixth through holes, the plurality of seventh through holes and the plurality of eighth through holes may correspond one to one.

[0115] Optionally, the beam splitter 24 can be used to connect the EB through a plurality of sixth through holes. down1 The astigmatism corrector 25 can adjust the angle of the EB by multiple seventh through holes. down1 The astigmatism is corrected and transmitted to the second electron lens 26. The second electron lens 26 can transmit the multiple EBs after astigmatism correction through multiple eighth through holes. down1 The light is focused and transmitted to the scanner 23 through a plurality of fourth through holes.

[0116] For example, the beam splitter 24 can be a silicon wafer or a metal wafer, etc. The astigmatism corrector 25 and the second electron lens 26 can both be chips, etc. Of course, the beam splitter 24, the astigmatism corrector 25 and the second electron lens 26 can also be other types, which are not limited in the present embodiment.

[0117] In some embodiments, as Figure 1 and Figure 2 As shown, the electron source 1 may include an electron emitter 11 and a third electron lens 12. The third electron lens 12 may be single-stage or multi-stage.

[0118] The electron emitter 11 can be used to emit a third downward electron beam (which can be EB down3 denoted) to the third electron lens 12.

[0119] The third electron lens 12 can be used to: down3 Perform collimation processing to obtain EB down1 It can be seen that EB down1 Can be EB after collimation down3 .

[0120] Of course, in addition to EB down3The third electron lens 12 can also perform collimation on EB down3 The area and beam density can be adjusted.

[0121] For example, the third electron lens 12 may be a metal ring, a metal sheet, a magnetic coil, etc. Of course, the third electron lens 12 may also be in other forms, which is not limited in the embodiment of the present application.

[0122] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A focusing imaging device, characterized in that: Including electron source, intermediate lens group and focusing imaging lens group: The electron source is used to: output a first downward electron beam to the intermediate mirror group; The intermediate mirror assembly is used to: control the landing position of the first downward electron beam on the sample by scanning the first downward electron beam; The focusing imaging lens group is used to focus the first downward electron beam onto the surface of the sample according to the landing point position, and to perform imaging based on the upward electron beam generated on the surface of the sample.

2. The focusing imaging device according to claim 1, wherein: The focusing imaging lens assembly includes an electron detector and a first electron lens arranged in a stacked manner; The electron detector includes a first chip, and the first electron lens includes a plurality of second chips; the first chip and the plurality of second chips are stacked.

3. The focusing imaging device according to claim 2, characterized in that: The first chip is provided with a plurality of first through holes, and each of the plurality of second chips is provided with a plurality of second through holes; the plurality of second through holes corresponds one-to-one to the plurality of first through holes.

4. The focusing imaging device according to claim 3, characterized in that: The electron detector is used to: divide the first downlink electron beam into a plurality of second downlink electron beams through the plurality of first through holes; The first electron lens is used to: focus the plurality of second downlink electron beams onto the surface of the sample through the plurality of second through holes, or collect the uplink electron beams generated on the surface of the sample; The electron detector is further configured to detect the upward electron beam through the plurality of first through holes to perform imaging.

5. The focusing imaging device according to any one of claims 2 to 4, characterized in that: The electron detector is used to be grounded, the sample is used to receive a first voltage, and the first electron lens is used to receive a second voltage; wherein the voltage value of the first voltage is different from the voltage value of the second voltage; The first electron lens is used to focus the multiple second downward electron beams onto the surface of the sample according to the electric field formed by the voltage difference between the first voltage and the second voltage, or to collect the upward electron beam according to the electric field.

6. The focusing imaging device according to any one of claims 1 to 5, characterized in that: The intermediate mirror assembly includes a stacked deflector, a blocking assembly, and a scanner; the deflector includes a plurality of third through holes, the blocking assembly includes a plurality of fourth through holes; the scanner includes a plurality of fifth through holes; the plurality of third through holes, the plurality of fourth through holes, and the plurality of fifth through holes correspond to each other in a one-to-one manner; The deflector is used to: adjust the angle of the first downstream electron beam through the plurality of third through holes and transmit it to the scanner through the plurality of fourth through holes; The scanner is used to: scan the first downward electron beam after the angle is adjusted through the multiple fifth through holes, and control the landing position of the first downward electron beam after the angle is adjusted on the sample.

7. The focusing imaging device according to claim 6, characterized in that: The intermediate lens group further includes a beam splitter, an astigmatism corrector and a second electron lens; The beam splitter is located between the electron source and the deflector and is provided with a plurality of sixth through holes; the astigmatism corrector and the second electron lens are both located between the deflector and the blocking assembly, and the astigmatism corrector is provided with a plurality of seventh through holes, and the second electron lens is provided with a plurality of eighth through holes; The plurality of sixth through holes, the plurality of seventh through holes, and the plurality of eighth through holes correspond to each other one by one.

8. The focusing imaging device according to claim 6 or 7, characterized in that: The scanner includes a plurality of stacked third chips or a plurality of stacked metal multipoles.

9. The focusing imaging device according to any one of claims 1 to 8, characterized in that: The electron source includes an electron emitter and a third electron lens; The electron emitter is used to: emit a third downward electron beam to the third electron lens; The third electron lens is used to collimate the third downstream electron beam to obtain the first downstream electron beam.

10. A focusing imaging system, characterized in that: The invention comprises a machine platform and a focusing imaging device according to any one of claims 1 to 9; the focusing imaging device is arranged on the machine platform.

Images