Charged particle beam device, detection device, and detection method

Abstract

The embodiment of the invention provides a charged particle beam device, a detection device and a detection method, relates to the technical field of detection devices, and is used for improving the detection efficiency of charged particle beams. The charged particle beam apparatus comprises: an electron source for emitting a first charged particle beam; the first lens is used for focusing the first charged particle beam in response to a first excitation signal in a first mode; the first deflector is used for deflecting the focused first charged particle beam in response to a first deflection voltage in a first mode; and the objective lens is used for making the deflected first charged particle beam enter the sample in response to a second excitation signal in the first mode.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of detection devices, and in particular to a charged particle beam device, a detection device, and a detection method. Background Art

[0002] During the integrated circuit (IC) manufacturing process, circuit components must be inspected using inspection devices such as optical microscopes or charged particle beam microscopes to ensure they are free of defects. Currently, charged particle beam microscopes typically inspect circuit components using a single charged particle beam. Inspection devices that use multiple charged particle beams rely on mechanical devices to switch between pre-charging and imaging modes, and each charged particle beam has a relatively low beam current, resulting in lower efficiency in inspecting circuit components. Summary of the Invention

[0003] Embodiments of the present application provide a charged particle beam device, a detection device, and a detection method for improving the detection efficiency of the charged particle beam device.

[0004] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, a charged particle beam device is provided. The charged particle beam device includes: an electron source configured to emit a first charged particle beam; a first lens configured to focus the first charged particle beam in response to a first excitation signal in a first mode; a first deflector configured to deflect the focused first charged particle beam in response to a first deflection voltage in the first mode; and an objective lens configured to direct the deflected first charged particle beam onto a sample in response to a second excitation signal in the first mode.

[0006] In the first mode, the charged particle beam device provided in this embodiment uses a first lens to converge the charged particle beam to a single point, producing a higher-current charged particle beam and effectively increasing the pre-charge beam current density. Simultaneously, a first deflector can deflect the converged charged particle beam to a desired location. Finally, the deflected first charged particle beam is incident on the sample through an objective lens, enabling time- and zone-sharing pre-charging of the sample using the high-current-density charged particle beam, effectively increasing detection efficiency.

[0007] In one possible embodiment, the charged particle beam apparatus further includes a first beam splitting module disposed between the first deflector and the objective lens, the first beam splitting module being configured to deflect the first charged particle beam passing through the first deflector. Thus, the first beam splitting module implements functions such as correction and scanning deflection of each charged particle beam.

[0008] In one possible embodiment, the first lens is further configured to collimate the first charged particle beam in response to a third excitation signal in the second mode; the first beam splitting module is further configured to split the collimated first charged particle beam into multiple second charged particle beams; and the objective lens is further configured to focus the second charged particle beam in response to a fourth excitation signal in the second mode and direct it onto the sample. Thus, the charged particle beam device can switch between the first and second modes by adjusting the focusing power of the first lens, simplifying operation and further improving detection efficiency.

[0009] In a possible implementation, the charged particle beam device further includes a second lens disposed between the electron source and the first lens, and the second lens is used to collimate the first charged particle beam.

[0010] Considering the high-voltage risks associated with frequently changing the focusing power of the first lens to switch between the first and second modes when the first lens is an electric lens, and the hysteresis effect associated with frequently changing the focusing power of the first lens when the first lens is a magnetic lens, this embodiment also includes a second lens to process the first charged particle beam. This allows the first lens to focus the first charged particle beam only in the first mode and remain inactive in the second mode. This avoids these issues.

[0011] In a possible implementation, the charged particle beam device further includes a second beam splitting module disposed between the second lens and the first lens, and the second beam splitting module is configured to split the collimated first charged particle beam into a plurality of third charged particle beams.

[0012] This embodiment also includes a second beam-splitting module, which splits, switches on, and off the first charged particle beam. It can also switch off the beam in sections to effectively adjust and control the beam current of the third charged particle beam. Due to the blocking effect of the second beam-splitting module, the total beam current of the third charged particle beam is smaller than that of the first charged particle beam. Therefore, this embodiment is more suitable for samples requiring a small beam current, allowing the charged particle detection device to meet diverse detection requirements. The second beam-splitting module can also reduce Coulomb interactions and improve imaging resolution.

[0013] In a possible embodiment, the charged particle beam device further includes a second deflector arranged between the first deflector and the first beam splitting module, and the second deflector is used to deflect the first charged particle beam passing through the first deflector in response to a second deflection voltage in the first mode.

[0014] In this embodiment, when the charged particle beam device operates in the first mode, the first lens is used to converge the first charged particle beam to the same point, thereby obtaining a charged particle beam with a larger beam current, effectively improving the pre-charged beam current density, and thus increasing the detection efficiency; at the same time, the first deflector and the second deflector can be used to deflect the converged first charged particle beam to a specified position, and the deflected first charged particle beam is vertically incident on the sample, thereby realizing time-sharing and partitioned pre-charging of the sample, reducing the obstruction of the first charged particle beam by the remaining structures of the charged particle beam device, and further improving the beam current density of the charged particle beam.

[0015] In one possible embodiment, the objective lens is used to respond to the second excitation signal in the first mode to focus the first charged particle beam passing through the first beam splitting module and form a first light spot on the sample, and the size of the first light spot is smaller than the field of view of the charged particle beam device.

[0016] In one possible embodiment, the objective lens is used to respond to the second excitation signal in the first mode, causing the first charged particle beam incident through the first beam splitting module to be defocused and forming a first light spot on the sample, wherein the size of the first light spot is approximately equal to the field of view of the charged particle beam device.

[0017] In a possible implementation, the first lens is an electrostatic lens or a magnetic lens.

[0018] In a possible embodiment, the charged particle beam device further includes a detector, which is used to detect electrons emitted from the sample surface.

[0019] In a second aspect, a sample detection method is provided, comprising: emitting a first charged particle beam; focusing the first charged particle beam in a first mode; deflecting the focused first charged particle beam; and post-focusing the deflected first charged particle beam onto a sample.

[0020] In a possible embodiment, the detection method further includes: in the second mode, collimating the first charged particle beam; dividing the collimated first charged particle beam into multiple second charged particle beams; focusing the second charged particle beam and incident it on the sample.

[0021] In a third aspect, a detection device is provided, comprising: a controller and the charged particle beam device provided in the first aspect, wherein the controller is electrically connected to the charged particle beam device.

[0022] Among them, the technical effects brought about by any possible implementation of the second and third aspects can refer to the technical effects brought about by different implementations of the above-mentioned first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of image grayscale values corresponding to different potentials on the sample surface provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of the detection device provided in an embodiment of the present application;

[0025] Figure 3 A schematic structural diagram of a charged particle beam device provided in an embodiment of the present application;

[0026] Figure 4 A schematic structural diagram of a charged particle beam device provided in another embodiment of the present application;

[0027] Figure 5 A schematic structural diagram of a charged particle beam device provided in yet another embodiment of the present application;

[0028] Figure 6 A schematic structural diagram of a charged particle beam device provided in yet another embodiment of the present application;

[0029] Figure 7 Schematic diagram of two pre-charging modes of a charged particle beam device provided in an embodiment of the present application;

[0030] Figure 8 A schematic diagram of focusing a charged particle beam within a single field of view provided in an embodiment of the present application;

[0031] Figure 9 A schematic diagram of a charged particle beam device provided in an embodiment of the present application in a second mode;

[0032] Figure 10 A schematic structural diagram of a charged particle beam device provided in yet another embodiment of the present application;

[0033] Figure 11 A schematic structural diagram of a charged particle beam device provided in yet another embodiment of the present application;

[0034] Figure 12 A schematic structural diagram of a charged particle beam device provided in yet another embodiment of the present application;

[0035] Figure 13 A schematic diagram of the flow chart of the sample detection method provided in the embodiment of the present application;

[0036] Figure 14 A schematic flow chart of the sample detection method provided in the embodiments of the present application. DETAILED DESCRIPTION

[0037] In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0038] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0039] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more. In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0040] Many circuit devices can be formed together on the same silicon wafer, and this is called an integrated circuit, or IC. The size of these circuit devices has been significantly reduced, so multiple circuit devices can be mounted on the same wafer. Manufacturing this integrated circuit typically involves hundreds of separate steps, and even an error in a single step can cause defects in the finished IC, causing it to malfunction. Therefore, inspection equipment is needed to perform inspections at various stages of integrated circuit formation to improve the yield of the integrated circuit.

[0041] The detection device can be a charged particle (e.g., electron) beam microscope, such as a scanning electron microscope (SEM), which can be used to inspect circuit devices on wafers smaller than 100 nanometers in size. For example, electron beam inspection (EBI) can be used to detect defects in circuit devices. EBI utilizes the information generated by the interaction of high-energy electrons with the sample surface material to generate images, which are then processed and computed to detect the sample. Voltage contrast (VC) is a commonly used analytical technique for semiconductor process inspection. When the incident charged particle beam undergoes an inelastic collision with the sample material, some electrons outside the nucleus gain energy and migrate to the sample surface. These electrons are called secondary electrons (SEs), resulting in a non-uniform total electron yield on the sample surface. The accumulation of positive and negative charges on the sample surface causes the number of SEs emitted to change, and the grayscale value of the image in the inspection area changes accordingly. Figure 1 (a) in the figure shows that after negative voltage contrast (NVC) charging, the sample surface exhibits a negative potential due to the accumulation of negative charges, the number of SE emissions is greater, and the image of the detection area is brighter. Figure 1 (2) in the figure shows that after positive voltage contrast (PVC) charging, the sample surface exhibits a positive potential due to the enrichment of positive charges, the number of SE emissions is smaller, and the image of the detection area is darker.

[0042] The detector inside the SEM detects SE and then images it. By accumulating charge on the sample surface, the strength of the SE signal can be used to determine whether the metal contact layer is successfully connected to the underlying layer. This allows for the detection of electrical defects caused by the etching process, such as opens, shorts, and leakage.

[0043] In other examples, primary beam flooding (PBF), flood gun (FG), or advanced charging control (ACC) methods can be used to control the secondary electron yield on the sample surface, thereby changing the surface potential and then detecting defects in logic and memory devices.

[0044] The embodiment of the present application provides a detection device. Figure 2As shown, the inspection apparatus includes a main chamber 101, a load / lock chamber 102, a charged particle beam device 104, an equipment front-end module (EFEM) 106, and a controller 109. The charged particle beam device 104 is located within the main chamber 101. The charged particle beam device 104 can be a single-beam system or a multi-beam system. The controller 109 is electrically connected to the charged particle beam device 104. The controller 109 can be a computer configured to perform various controls of the EBI system. The EFEM 106 includes a first load port 106a and a second load port 106b. The EFEM 106 may include additional load ports. The first load port 106a and the second load port 106b can receive wafer transport pods (FOUPs) containing wafers (e.g., semiconductor wafers or wafers made of other materials) or samples to be inspected (wafers and samples are collectively referred to as "samples" hereinafter). One or more robotic arms (not shown) in the EFEM 106 can transport the samples to the load / lock chamber 102.

[0045] The load / lock chamber 102 is connected to a load / lock vacuum pump system (not shown) that removes gas molecules in the load / lock chamber 102 to reach a first pressure below atmospheric pressure. After reaching the first pressure, one or more robotic arms (not shown) can transport the sample from the load / lock chamber 102 to the main chamber 101. The main chamber 101 is connected to a main chamber vacuum pump system (not shown) that removes gas molecules in the main chamber 101 to reach a second pressure below the first pressure. After reaching the second pressure, the sample is immersed in or inspected by the charged particle beam device 104.

[0046] The controller 109 may be electrically connected to the charged particle beam device 104 and may also be electrically connected to other components. The controller 109 may be a computer configured to perform various controls on the detection device. The controller 109 may also include processing circuitry configured to perform various signal and image processing functions. Although the controller 109 is Figure 2 106, but it will be appreciated that the controller 109 may be part of the structure.

[0047] The embodiment of the present application further provides a charged particle beam device 104. The charged particle beam device 104 includes an electron source 110 for generating a charged particle beam along a main optical axis; a first aperture array 115 including a plurality of first apertures with different apertures, for example Figure 3The first aperture 115-1, the first aperture 115-2 and the first aperture 115-3 shown in the figure are used to allow at least a first portion of the charged particle beam to pass through; the beam-forming lens 120 is used to focus at least the first portion of the charged particle beam based on a selected operating mode of the device, wherein the selected operating mode includes a first mode and a second mode; and the aperture plate 125 includes a plurality of second apertures with different apertures, such as Figure 3 The second aperture 125-1, the second aperture 125-2 and the second aperture 125-3 are shown in FIG. The second aperture is used to form the second part of the charged particle beam, the objective lens 130 is used to make the second part of the charged particle beam incident on the surface of the sample 150, and the detector 165 is used to detect electrons emitted from the sample surface.

[0048] In this embodiment, if Figure 3 As shown by the solid line in FIG, in the first mode, the charged particle beam is incident with a large beam through the first aperture array 115-1, passes through the condenser lens 120, and the focus coincides with the plane of the aperture plate 125. Finally, the objective lens 130 expands the beam, so that substantially all the charged particles in the second part of the charged particle beam are used to flood the surface of the sample, thereby pre-charging the surface of the sample. Figure 3 As shown by the dotted line in the figure, in the second mode, the charged particle beam is incident with a small beam flow through the first aperture array 115-3, and after passing through the focusing lens 120, the focus coincides with the plane of the aperture plate 125. A second aperture with a smaller aperture in the aperture plate 125, such as the second aperture 125-3, can be used to further reduce the beam flow of the charged particle beam. Finally, by focusing of the objective lens 130, at least some of the charged particles in the second part of the charged particle beam are used to inspect the surface of the sample and achieve sample imaging.

[0049] Although the electron source of this system can be designed as a single-beam electron beam mode or a multi-beam electron beam mode, for the multi-beam electron beam mode, structures such as the first aperture array 115, the focusing lens 120, the aperture plate 125, and the objective lens 130 need to be applied to each beam, which greatly increases the complexity of the system and greatly increases the difficulty of control. On the other hand, each charged particle beam in the multi-beam electron beam mode can only charge the sample in its corresponding area, and the beam current is much smaller than the total beam current of all the multiple charged particle beams converged into a single beam mode. When the total amount of charged charge is the same, the charged particle beam device 104 will seriously affect the detection efficiency. Therefore, the charged particle beam device 104 is more suitable for a single electron beam detection system. Finally, the switching between the pre-charging mode and the imaging mode of the system relies on the mechanical movement of the first aperture array and the change of the focusing ability of the focusing lens and the objective lens. This mode switching method will result in a very low detection efficiency.

[0050] It is understandable that the charged particle beam device 104 further includes a translation stage for moving the sample 150 , thereby ensuring that the charged particle beam can detect other areas of the sample.

[0051] The present application also provides a charged particle beam device 104. Figure 4 The charged particle beam device 104 includes an electron source 110 for generating a charged particle beam along a main optical axis; a first aperture array 115 including a plurality of first apertures with different apertures, for example Figure 3 The first aperture 115-1, the first aperture 115-2 and the first aperture 115-3 shown in the figure, the first aperture array 115 is used to allow at least the first part of the charged particle beam to pass through; the beam-forming lens 120 is used to focus at least the first part of the charged particle beam; the objective lens 130, the objective lens 130 is used to focus at least the first part of the charged particle beam to the surface of the sample 150, or to focus at least the first part of the charged particle beam to the surface of the sample 150; the detector 165 is used to detect electrons emitted from the surface of the sample 150.

[0052] In this embodiment, the controller 109 can control the charged particle beam device 104 to switch between the first mode and the second mode. Figure 4 As shown by the solid line in FIG, in the first mode, the controller 109 is configured to move the motor of the first aperture array 115 so that the first aperture 115-1 with a larger aperture is aligned with the electron source 110, thereby setting the charged particle beam to a first current level. The objective lens 130 is then controlled to cause the charged particle beam to be incident on the sample 150 at the first current level, and the charged particle beam incident on the sample 150 is defocused.

[0053] like Figure 4 As shown by the dotted line in , in the second mode, the controller 109 is configured to control the motor for moving the first aperture array 115, move the first aperture array 115 so that the first aperture 115-2 with a smaller aperture is aligned with the electron source 110, thereby setting the charged particle beam to a second current level, and then control the objective lens 130 to make the charged particle beam incident on the sample 150 at the second current level, and the charged particle beam incident on the sample 150 is focused onto the surface of the sample 150, and the detector 165 detects electrons emitted from the surface of the sample 150.

[0054] The charged particle beam device 104 controls the beam size of the charged particles by mechanically adjusting the aperture size of the first aperture array, and the density of the beam is controlled by adjusting the spot size through the objective lens 130. On the other hand, the beam size of each charged particle beam is very small. Under the condition of the same charge amount, the charging time is longer, and therefore the detection efficiency is very low.

[0055] The present application also provides a charged particle beam device 104. Figure 5 The charged particle beam device 104 includes: an electron source 110, the electron source 110 is used to emit a first charged particle beam; a first lens 121, the first lens 121 is used to focus the first charged particle beam in response to a first excitation signal in a first mode; a first deflector 131, the first deflector 131 is used to deflect the focused first charged particle beam in response to a first deflection voltage in the first mode; and an objective lens 141, the objective lens 141 is used to respond to a second excitation signal in the first mode to cause the deflected first charged particle beam to be incident on the sample 150.

[0056] In the first mode, the charged particle beam device 104 provided in the embodiment of the present application uses the first lens 121 to converge the charged particle beam to the same point, thereby obtaining a charged particle beam with a larger beam current, effectively improving the pre-charged beam current density, thereby increasing the detection efficiency; at the same time, the first deflector 131 can be used to deflect the converged charged particle beam to a specified position. For example Figure 5 The optical path ① shown indicates that the first charged particle beam is directly incident vertically into the hole in the center of the first beam splitting module 161 without being deflected; Figure 5 The optical paths ② and ③ shown in the figure show that the first charged particle beam is deflected once and then obliquely incident on the non-central hole of the first beam splitting module 161. Finally, the deflected first charged particle beam is incident on the sample 150 through the objective lens 141, thereby achieving time-sharing and zone-sharing pre-charging of the sample.

[0057] In a specific embodiment, see Figure 6 The charged particle beam device 104 includes: an electron source 110 , a first lens 121 , a first deflector 131 , a first beam splitting module 161 and an objective lens 141 .

[0058] Illustratively, the electron source 110 may include a filament and electrodes, such as a cathode, an extraction electrode, an acceleration electrode, and a deflection electrode, wherein charged particles may be emitted from the cathode and extracted by the extraction electrode or accelerated by the acceleration electrode to form a first charged particle beam.

[0059] The first lens 121 can be an electrostatic lens or a magnetic lens. In the first mode, the first lens 121 can converge the parallel first charged particle beam to a single point. In the second mode, the first lens 121 can collimate the first charged particle beam emitted by the electron source 110 and form it into a planar parallel electron beam to reduce the divergence angle of the first charged particle beam, thereby switching between the first and second modes.

[0060] The first deflector 131 can be an electric deflector or a magnetic deflector, which can deflect the focused charged particle beam and deflect the first charged particle beam in the first mode, thereby pre-charging the sample 150 in a zoned and timed manner.

[0061] The first beam splitting module 161 can be composed of an aperture 1611 and a third deflector 1612. The aperture 1611 can split a single first charged particle beam into multiple beams, and use the third deflector 1612 to achieve functions such as correction, scanning deflection, etc. for each charged particle beam.

[0062] In some optional embodiments, the charged particle beam device 104 further includes a detector 165. The detector 165 is, for example, a porous array detector 165 manufactured using a MEMS process, and is primarily used to detect signals such as secondary electrons and backscattered electrons to achieve an imaging function. The detector 165 can be positioned above the first beam splitting module 161, between the first beam splitting module 161 and the objective lens 141, or below the objective lens 141, depending on overall requirements. This is not limited to the embodiments of the present application.

[0063] When the charged particle beam device 104 operates in the first mode, the electron source 110 emits the first charged particle beam; the first lens 121 responds to the first excitation signal in the first mode sent by the controller 109 to improve its focusing ability and focus the first charged particle beam; then the first deflector 131 responds to the first deflection voltage in the first mode to deflect the focused first charged particle beam; Figure 6 The three optical paths shown in (a) are: Figure 6 The optical path ① shown in (a) indicates that the first charged particle beam is directly incident vertically onto the hole in the center of the aperture 1611 in the first beam splitting module 161 without being deflected; Figure 6 The optical path ② shown in (a) indicates that the first charged particle beam is deflected once and is obliquely incident on the non-central hole of the aperture 1611; Figure 6 The optical path ③ shown in (a) in FIG. 1 shows that the first charged particle beam undergoes two deflections and is vertically incident on a non-central hole in aperture 1611. Finally, in response to the second excitation signal in the first mode sent by controller 109, objective lens 141 directs the first charged particle beam, which has passed through first beam splitting module 161, onto the sample, thereby precharging sample 150.

[0064] It is understandable that the first charged particle beam may not be deflected after passing through the first deflector 131 and may directly enter the aperture 1611. For example Figure 7The aperture 1611 structure shown in FIG. 1 is provided with a 3×3 array of holes. The first charged particle beam can pass through the first deflector 131 without being deflected and vertically incident on the holes in the second row and second column of the aperture 1611. Correspondingly, the first charged particle beam can also be deflected after passing through the first deflector 131 and vertically incident on the other holes in the aperture 1611. When there is no hole located in the center of the aperture 1611, for example, when the aperture 1611 is provided with a 4×3 array of holes, the first charged particle beam can be deflected by the first deflector 131 and incident on each hole in the aperture 1611 in turn.

[0065] In the embodiment of the present application, local pre-charging and global pre-charging of the sample 150 can be achieved by controlling the first deflector 131. Figure 7 (1) in the figure indicates that only a part of the sample 150 is locally pre-charged, for example, the first area 151 of the sample 150 is charged sequentially through the objective lens 141. Figure 7 (2) in the figure indicates that global precharging is performed on the entire area of sample 150.

[0066] In an optional embodiment, the objective lens 141 is used to respond to the second excitation signal in the first mode to focus the first charged particle beam passing through the first beam splitting module 161 and form a first light spot on the sample, wherein the size of the first light spot is smaller than the field of view (FOV) of the charged particle beam device 104. Figure 8 As shown in (1), in the high-density flooding mode, the charged particle beam enters the objective lens 141 and is further focused on the surface of the sample 150 to form a first light spot. For example, the diameter of the first light spot is 0 to 10 microns, the beam density is large, and the field of view of the charged particle beam device 104 is 10 to 100 microns. The size of the first light spot is smaller than the field of view of the charged particle beam device 104, so the first charged particle beam needs to be scanned and pre-charged within the field of view. For example, the first charged particle beam can be deflected by controlling the third deflector 1612 in the first beam splitting module 161 so that the first light spot is formed at different positions within the field of view, thereby enabling the first charged particle beam to be scanned and pre-charged within the field of view.

[0067] In an optional embodiment, the objective lens 141 is used to respond to the second excitation signal in the first mode, causing the first charged particle beam incident through the first beam splitting module 161 to be defocused and forming a first light spot on the sample, the size of the first light spot being approximately equal to the field of view of the charged particle beam device 104. Figure 8As shown in (2), in the low-density flooding mode, the charged particle beam device 104 defocuses the first charged particle beam onto the sample to be measured 150 after entering the objective lens 141 and performs pre-charging. For example, the diameter of the first spot is 10 to 100 microns, the beam density is small, and the diameter is close to the size of the field of view of the charged particle beam device 104. For example, the first charged particle beam can be deflected by controlling the third deflector 1612 in the first beam splitting module 161 to adjust the position where the first spot is formed, so that the sample 150 within the field of view can be pre-charged by the first charged particle beam.

[0068] It can be understood that in this embodiment, the size of the first light spot is close to the field of view of the charged particle beam device 104, which can be understood as the size of the first light spot is absolutely equal to or approximately equal to the field of view of the charged particle beam device 104, where the acceptable deviation range of approximately equal can be, for example, the difference between the two is less than or equal to 5% of either one.

[0069] Thus, when the charged particle beam device 104 operates in the first mode, after the first charged particle beam converged by the first lens 121 enters the objective lens 141, the objective lens 141 can refocus or defocus the first charged particle beam to obtain light spots of different sizes and beam densities. Thus, by adjusting the focusing capability of the objective lens 141, the first charged particle beam can be refocused or defocused, thereby enabling pre-charging of the sample 150 using first charged particle beams of different beam densities, providing multiple pre-charging modes.

[0070] like Figure 6 As shown in (2), when the charged particle beam device 104 operates in the second mode, after the electron source 110 emits the first charged particle beam, the first lens 121 collimates the first charged particle beam in response to the third excitation signal in the second mode sent by the controller 109, and each particle beam in the collimated first charged particle beam is emitted in parallel, and the first deflector 131 does not deflect the collimated first charged particle beam, that is, the excitation applied to the first deflector 131 is 0. For example, when the first deflector 131 is an electric deflector, the deflection voltage applied to the first deflector 131 is 0; when the first deflector 131 is a magnetic deflector, the deflection current applied to the first deflector 131 is 0. Then the grating in the first beam splitting module 161 splits the collimated first charged particle beam into multiple second charged particle beams; the objective lens 141 focuses the second charged particle beam in response to the fourth excitation signal in the second mode sent by the controller 109, and incidents it onto the sample, and the detector 165 detects the electrons emitted from the surface of the sample 150 and sends them to the controller 109, thereby achieving imaging.

[0071] In some specific examples, when the charged particle beam device 104 operates in the second mode, a schematic diagram of multiple second charged particle beams scanning within the field of view is shown in FIG. Figure 9 As shown, after being focused by the objective lens 141, the second charged particle beam forms a second light spot on the surface of the sample 150. The second light spot has a size of 1-100 nanometers, which facilitates high-resolution imaging. Because the size of the second light spot is smaller than the field of view of the charged particle beam device 104, the charged particle beam device 104 can deflect each second charged particle beam by controlling the third deflector 1612 in the first beam splitting module 161 to adjust the formation position of the second light spot, thereby enabling imaging of the sample 150 within the field of view using the first charged particle beam.

[0072] In some embodiments, the controller 109 may include an image processing system comprising an image acquisition device (not shown) and a storage device (not shown). The image acquisition device may include one or more processors. For example, the image acquisition device may include a computer, server, mainframe, terminal, personal computer, any type of mobile computing device, or a combination thereof. The image acquisition device may be communicatively coupled to the charged particle beam detector 165 via a medium such as an electrical conductor, a fiber optic cable, a portable storage medium, IR, Bluetooth, the Internet, a wireless network, radio, or a combination thereof. In some embodiments, the image acquisition device may receive signals from the electron detector and construct an image. Thus, the image acquisition device may acquire an image of a region of the sample 150. The image acquisition device may also perform various post-processing functions, such as generating outlines and overlaying indicators on the acquired image. The image acquisition device may be configured to adjust brightness and contrast, etc., on the acquired image. In some embodiments, the storage device may be a storage medium such as a hard drive, a flash drive, cloud storage, random access memory (RAM), or other types of computer-readable memory. The storage device may be coupled to the image acquisition device and may be used to save scanned raw image data as an initial image and to save post-processed images.

[0073] In some embodiments, the controller 109 may include a measurement circuit system (e.g., an analog-to-digital converter) to obtain the distribution of the detected secondary electrons. The electron distribution data collected within the detection time field of view is combined with the corresponding scan path data of the charged particle beam incident on the surface of the sample 150 (e.g., a wafer) to reconstruct an image of the wafer structure under inspection. The reconstructed image can be used to reveal various features of the internal or external structure of the sample 150, thereby revealing any defects that may be present in the sample 150.

[0074] The present application also provides a charged particle beam device 104, see Figure 10The charged particle beam device 104 includes: an electron source 110, a first lens 121, a first deflector 131, a second deflector 132, a first beam splitting module 161, an objective lens 141 and a detector 165.

[0075] like Figure 10 As shown, when the charged particle beam device 104 operates in the first mode, the electron source 110 emits the first charged particle beam; the first lens 121 responds to the first excitation signal in the first mode sent by the controller 109, improves its own focusing ability, and focuses the first charged particle beam; then the first deflector 131 responds to the first deflection voltage in the first mode to deflect the focused first charged particle beam; the second deflector 132 responds to the second deflection voltage in the first mode to perform a second deflection on the first charged particle beam passing through the first deflector 131, and the first charged particle beam deflected by the second deflector 132 is vertically incident on the first beam splitting module 161, thereby avoiding part of the first charged particle beam being blocked by the first beam splitting module 161 and unable to be incident on the surface of the sample 150.

[0076] It is understandable that this embodiment does not limit the number of deflections of the charged particle beam. In other optional embodiments, when the charged particle beam device 104 operates in the first mode, the electron source 110 emits the first charged particle beam; the first lens 121 responds to the first excitation signal in the first mode sent by the controller 109 to improve its focusing ability and focus the first charged particle beam; then the first deflector 131 does not deflect the focused first charged particle beam, that is, the excitation applied to the first deflector 131 is 0; the second deflector 132 responds to the second deflection voltage in the first mode to deflect the first charged particle beam, that is, the first charged particle beam is deflected only once, and the first charged particle beam deflected by the second deflector 132 is obliquely incident on the first beam splitting module 161.

[0077] See also Figure 10 The three light paths shown are Figure 10 The optical path ① in the figure indicates that the optical path passes through the first deflector 131 and the second deflector 132 without being deflected and directly enters the hole at the center of the aperture 1611 in the first beam splitting module 161 vertically; Figure 10 The light path ② in the figure indicates that after two deflections, it is vertically incident on the non-center hole of the aperture 1611. Figure 10 Light path ③ in FIG represents a single deflection, resulting in oblique incidence into a non-central hole in aperture 1611. Finally, in response to the second excitation signal in the first mode sent by controller 109, objective lens 141 directs the first charged particle beam, which has passed through first beam splitting module 161, onto the sample, thereby precharging sample 150.

[0078] When the charged particle beam device 104 operates in the second mode, after the electron source 110 emits the first charged particle beam, the first lens 121 responds to the third excitation signal in the second mode sent by the controller 109 to collimate the first charged particle beam, and the individual particle beams in the collimated first charged particle beam are emitted in parallel. The first deflector 131 and the second deflector 132 do not deflect the collimated first charged particle beam, that is, the excitation applied to the first deflector 131 and the second deflector 132 is 0, and then the grating in the first beam splitting module 161 divides the collimated first charged particle beam into multiple second charged particle beams; the objective lens 141 responds to the fourth excitation signal in the second mode sent by the controller 109 to focus the second charged particle beam and incident it on the sample, and the detector 165 detects the electrons emitted from the surface of the sample 150 and sends them to the controller 109, thereby achieving imaging.

[0079] Thus, when the charged particle beam device 104 operates in the first mode, the first lens 121 is used to converge the first charged particle beam to a single point, resulting in a charged particle beam with a larger current, effectively increasing the pre-charge beam current density and thereby improving detection efficiency. Simultaneously, the first deflector 131 and the second deflector 132 can be used to deflect the converged first charged particle beam to a specified position. The deflected first charged particle beam is then incident on the sample, thereby enabling time-sharing and zone-sharing pre-charging of the sample 150. This reduces the detection device's requirements and reliance on the translation stage when pre-charging large-area samples 150. Furthermore, the charged particle beam device 104 can switch between the first and second modes by adjusting the focusing power of the first lens 121, simplifying operation and further improving detection efficiency.

[0080] The present application also provides a charged particle beam device 104. Figure 11 The charged particle beam device 104 includes: an electron source 110, a second lens 122, a first lens 121, a first deflector 131, a second deflector 132, a first beam splitting module 161, an objective lens 141 and a detector 165.

[0081] like Figure 11As shown in (1), when the charged particle beam device 104 operates in the first mode, the electron source 110 emits the first charged particle beam; the second lens 122 collimates the first charged particle beam, and the individual particle beams in the collimated first charged particle beam are emitted in parallel. The first lens 121 responds to the first excitation signal in the first mode sent by the controller 109, improves its own focusing ability, and focuses the first charged particle beam; then the first deflector 131 responds to the first deflection voltage in the first mode to deflect the focused first charged particle beam, and the second deflector 132 responds to the second deflection voltage in the first mode to perform a second deflection on the first charged particle beam after passing through the second deflector 132. After passing through the second deflector 132, the first charged particle beam is vertically incident on the aperture 1611 in the first beam splitting module 161. Alternatively, the first deflector 131 does not deflect the focused first charged particle beam; the second deflector 132 responds to the second deflection voltage in the first mode, causing the first charged particle beam deflected by the second deflector 132 to be obliquely incident into the first beam splitting module 161. Figure 11 The three optical paths shown in (a) are: Figure 11 The optical path ① shown in (a) indicates that the optical path ① passes through the first deflector 131 and the second deflector 132 without being deflected and is directly incident vertically on the hole in the center of the aperture 1611 in the first beam splitting module 161; the optical path ② indicates that after two deflections, the optical path ③ is incident vertically on the non-center hole of the aperture 1611. The optical path ③ indicates that after one deflection, the optical path is obliquely incident on the non-center hole of the aperture 1611. Finally, the objective lens 141 responds to the second excitation signal in the first mode sent by the controller 109, and the first charged particle beam passing through the first beam splitting module 161 is incident on the sample, thereby completing the pre-charging of the sample 150.

[0082] like Figure 11 As shown in (2), when the charged particle beam device 104 operates in the second mode, after the electron source 110 emits the first charged particle beam, the second lens 122 collimates the first charged particle beam. After the collimation, the individual particle beams in the first charged particle beam are emitted in parallel. The first lens 121 does not process the first charged particle beam, that is, the excitation applied to the first lens 121 is 0. The first deflector 131 and the second deflector 132 do not deflect the collimated first charged particle beam, that is, the excitation applied to the first deflector 131 is 0. Then, the grating in the first beam splitting module 161 splits the collimated first charged particle beam into multiple second charged particle beams. The objective lens 141 focuses the second charged particle beam in response to the fourth excitation signal in the second mode sent by the controller 109 and makes it incident on the sample. The detector 165 detects the electrons emitted from the surface of the sample 150 and sends them to the controller 109, thereby achieving imaging.

[0083] Because the charged particle beam device 104 provided in the aforementioned embodiment requires frequent changes in the focusing capability of the first lens 121 to switch between the first mode and the second mode, when the first lens 121 is an electric lens, rapidly changing the electric lens voltage may bring about a high voltage risk; and when the first lens 121 is a magnetic lens, repeated magnetization of the magnetic lens may produce a hysteresis effect. Therefore, based on the aforementioned embodiment, the embodiment of the present application further provides a second lens 122, which processes the first charged particle beam. In this way, the first lens 121 only needs to focus the first charged particle beam in the first mode and does not operate in the second mode, thereby avoiding the above-mentioned problems.

[0084] The embodiment of the present application also provides a charged particle beam device 104. Figure 12 As shown, the charged particle beam device 104 includes: an electron source 110 , a second lens 122 , a second beam splitting module 162 , a first lens 121 , a first deflector 131 , a second deflector 132 , a first beam splitting module 161 , an objective lens 141 and a detector 165 .

[0085] like Figure 12 As shown in (1), when the charged particle beam device 104 works in the first mode, the electron source 110 emits the first charged particle beam; the second lens 122 collimates the first charged particle beam, and the various particle beams in the collimated first charged particle beam are emitted in parallel. The second beam splitting module 162 divides the collimated first charged particle beam into multiple third charged particle beams. The first lens 121 responds to the first excitation signal in the first mode sent by the controller 109 to improve its own focusing ability and focus the third charged particle beam; then the first deflector 131 responds to the first deflection voltage in the first mode to deflect the focused third charged particle beam, and the second deflector 132 responds to the second deflection voltage in the first mode to perform a second deflection on the third charged particle beam, and the deflected third charged particle beam is vertically incident on the first beam splitting module 161. See Figure 12 The two optical paths shown in (a) are: Figure 12 The optical path ① shown in (a) indicates that the light beam passes through the first deflector 131 and the second deflector 132 without being deflected and is directly incident vertically into the hole in the center of the aperture 1611 in the first beam splitting module 161; the optical path ② indicates that after two deflections, the light beam is incident vertically into the non-center hole of the aperture 1611. The optical path ③ indicates that the first charged particle beam is not deflected after passing through the first deflector 131, and is obliquely incident into the first beam splitting module 161 after being deflected by the second deflector 132. Finally, the objective lens 141 responds to the second excitation signal in the first mode sent by the controller 109, and the third charged particle beam passing through the first beam splitting module 161 is incident on the sample, thereby completing the pre-charging of the sample 150.

[0086] like Figure 12 As shown in (2), when the charged particle beam device 104 operates in the second mode, after the electron source 110 emits the first charged particle beam, the second lens 122 collimates the first charged particle beam. The individual particle beams in the collimated first charged particle beam are emitted in parallel. The second beam splitting module 162 splits the collimated first charged particle beam into multiple third charged particle beams. The first lens 121 does not process the third charged particle beam. The first deflector 131 and the second deflector 132 do not deflect the collimated third charged particle beam, that is, the excitation applied to the first deflector is 0. Then, the grating in the first beam splitting module 161 splits the collimated third charged particle beam into multiple fourth first charged particle beams. The objective lens 141 focuses the fourth first charged particle beam in response to the fourth excitation signal in the second mode sent by the controller 109 and incidents it on the sample. The detector 165 detects electrons emitted from the surface of the sample 150 and sends them to the controller 109, thereby achieving imaging.

[0087] In this embodiment, a second beam splitting module 162 is also provided to split, shut down and open the first charged particle beam, and can also be shut down in sections to effectively adjust and control the size of the beam current of the third charged particle beam. At the same time, due to the blocking of the second beam splitting module 162, the total beam current of the third charged particle beam is smaller than the beam current of the first charged particle beam. Therefore, this embodiment is more suitable for samples 150 that require small beam current detection, so that the charged particle detection device can meet different detection requirements. At the same time, the second beam splitting module 162 can also reduce Coulomb interaction and improve imaging resolution.

[0088] It should be noted that, in the embodiment of the present application, the number of deflectors in the charged particle beam device 104 is not limited to two. In other examples, the charged particle beam device 104 may include a greater number of deflectors, for example, Figure 10 Based on the device shown in FIG. , a third deflector is further included. The third deflector can be used to control the deflection of the first charged particle beam so that the deflected first charged particle beam is not incident on the sample surface, thereby controlling the on / off of the first mode. Those skilled in the art can set the number and function of the deflectors in the charged particle beam device 104 and the number of deflections of the charged particle beam according to actual conditions.

[0089] refer to Figure 13 , Figure 13 A flow chart of a sample detection method according to an embodiment of the present application is shown. The detection method can be performed by, for example Figure 2 The controller 109 in the detection device shown is executed. The controller 109 can be programmed with the following detection method. For example, the controller 109 can send a first excitation signal in a first mode to the first lens to adjust the focus of the charged particle beam based on the first mode and perform other functions.

[0090] The detection method includes: emitting a first charged particle beam; focusing the first charged particle beam in a first mode; deflecting the focused first charged particle beam; and post-focusing the deflected first charged particle beam onto a sample.

[0091] In this embodiment, by converging the charged particle beams to the same point, a charged particle beam with a larger beam current is obtained, which effectively improves the pre-charged beam current density and thus increases the detection efficiency; at the same time, the converged charged particle beam is deflected to a specified position, and then the deflected first charged particle beam is incident on the sample, thereby realizing time-sharing and partitioned pre-charging of the sample, which can effectively improve the detection efficiency.

[0092] In an optional embodiment, if Figure 14 As shown, the detection method further includes: in the second mode, collimating the first charged particle beam; dividing the collimated first charged particle beam into multiple second charged particle beams; focusing the second charged particle beam and incident it on the sample.

[0093] In this embodiment, in the first mode, the first charged particle beam is converged to a single point to produce a higher-current charged particle beam, effectively increasing the pre-charging beam current density. Simultaneously, the converged first charged particle beam is deflected to a designated location and incident upon the sample, thereby achieving time-sharing and zone-sharing pre-charging of the sample and improving detection efficiency. Furthermore, after pre-charging the sample, the beam current density of the first charged particle beam can be adjusted to switch between the first and second modes, thereby imaging the sample and facilitating detection. This detection method is simple to operate and further improves detection efficiency.

[0094] It is understandable that in some examples, after the sample is pre-charged, the final imaging result cannot meet the preset requirements, such as low imaging resolution. The sample can also be pre-charged multiple times with reference to the above detection method until the imaging meets the preset requirements.

[0095] The above are only specific embodiments of the present application, but the scope of protection of this 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 this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A charged particle beam device, characterized in that include: an electron source configured to emit a first charged particle beam; a first lens, configured to focus the first charged particle beam in response to a first excitation signal in a first mode; a first deflector, configured to deflect the focused first charged particle beam in response to a first deflection voltage in a first mode; An objective lens is used to make the deflected first charged particle beam incident on a sample in response to a second excitation signal in a first mode.

2. The charged particle beam device according to claim 1, wherein The charged particle beam device further includes a first beam splitting module disposed between the first deflector and the objective lens, and the first beam splitting module is configured to deflect the first charged particle beam passing through the first deflector.

3. The charged particle beam device according to claim 2, wherein The first lens is further configured to collimate the first charged particle beam in response to a third excitation signal in the second mode; The first beam splitting module is further used to split the collimated first charged particle beam into a plurality of second charged particle beams; The objective lens is further configured to focus the second charged particle beam in response to a fourth excitation signal in the second mode, and to focus the second charged particle beam and allow the beam to be incident on the sample.

4. The charged particle beam device according to claim 1 or 2, characterized in that The charged particle beam device further includes a second lens disposed between the electron source and the first lens, and the second lens is used for collimating the first charged particle beam.

5. The charged particle beam device according to claim 4, wherein The charged particle beam device further includes a second beam splitting module disposed between the second lens and the first lens, and the second beam splitting module is used to split the first charged particle beam after the collimation process into a plurality of third charged particle beams.

6. The charged particle beam device according to any one of claims 1 to 5, characterized in that The charged particle beam device further includes a second deflector disposed between the first deflector and the first beam splitting module, the second deflector being configured to deflect the first charged particle beam passing through the first deflector in response to a second deflection voltage in a first mode.

7. The charged particle beam device according to any one of claims 1 to 6, characterized in that The objective lens is used to focus the first charged particle beam passing through the first beam splitting module in response to the second excitation signal in the first mode and form a first light spot on the sample. The size of the first light spot is smaller than the field of view of the charged particle beam device.

8. The charged particle beam device according to any one of claims 1 to 6, characterized in that The objective lens is used to respond to the second excitation signal in the first mode to defocus the first charged particle beam incident through the first beam splitting module and form a first light spot on the sample, the size of which is approximately equal to the field of view of the charged particle beam device.

9. The charged particle beam device according to any one of claims 1 to 8, characterized in that The first lens is an electrostatic lens or a magnetic lens.

10. The charged particle beam device according to any one of claims 1 to 9, characterized in that The charged particle beam device further includes a detector, which is used to detect electrons emitted from the sample surface.

11. A sample detection method, characterized in that: include: emitting a first charged particle beam; In a first mode, focusing the first charged particle beam; deflecting the focused first charged particle beam; The deflected first charged particle beam is post-focused onto a sample.

12. The method according to claim 11, characterized in that The detection method further comprises: In a second mode, collimating the first charged particle beam; dividing the collimated first charged particle beam into a plurality of second charged particle beams; The second charged particle beam is focused and incident on the sample.

13. A detection device, characterized in that: include: A controller and the charged particle beam device according to any one of claims 1 to 10, wherein the controller is electrically connected to the charged particle beam device.

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