Charged particle beam imaging device

Abstract

The present application discloses a charged particle beam imaging device, comprising: a housing, comprising a plurality of cavities, the plurality of cavities being connected along a direction parallel to the optical axis of the charged particle beam imaging device; a movable aperture, arranged in the housing and located between two adjacent cavities, the movable aperture comprising a main body, the main body being provided with a plurality of aperture holes, the apertures of the plurality of aperture holes being mutually unequal; the main body being movably arranged so as to move any aperture hole to the optical axis so that the two cavities on both sides of the movable aperture are connected through the aperture hole, thereby allowing the charged particle beam to pass through the aperture hole along the direction of the optical axis. The charged particle beam imaging device disclosed in the present application can increase the application range of the charged particle beam imaging device.

Description

Technical Field

[0001] The present application relates to the field of semiconductor detection technology, and in particular to a charged particle beam imaging device. Background Art

[0002] Charged particle beam detection and imaging equipment is widely used in the semiconductor industry, such as scanning electron microscopes, environmental scanning electron microscopes, electron beam defect detection equipment, electron beam critical dimension measurement equipment, focused ion beam microscopes, dual beam microscopes, etc. In order to ensure the stable operation and service life of the charged particle beam generation part (generally referred to as electron guns and ion guns) and improve the imaging quality, it is necessary to increase the vacuum degree of the charged particle beam path area as much as possible, generally requiring high vacuum to ultra-high vacuum levels. On the other hand, due to the need to maintain the sample or the actual detection speed, the vacuum degree in the area where the sample is located may be low. Therefore, when designing a charged particle beam imaging device or equipment, a gradient vacuum design (also known as differential vacuum) is required, that is, by adopting multiple vacuum cavities, vacuum pumps, and vacuum isolation modules, etc., to achieve and maintain the difference in vacuum degrees in different areas.

[0003] A hole structure with a fixed aperture is set between multiple connected vacuum chambers to connect them. The aperture is generally within the millimeter level, which is used to limit gas diffusion and thus achieve vacuum degrees inside different chamber areas. Therefore, the vacuum gradient between connected vacuum chambers is a fixed value, which limits the scope of application of charged particle beam detection imaging equipment. Summary of the invention

[0004] The embodiment of the present application provides a charged particle beam imaging device, which can increase the application scope of the charged particle beam imaging device.

[0005] An embodiment of the present application provides a charged particle beam imaging device, comprising: a shell, comprising a plurality of cavities, the plurality of cavities being connected along a direction parallel to the optical axis of the charged particle beam imaging device; a movable aperture, arranged in the shell and located between two adjacent cavities, the movable aperture comprising a main body, the main body being provided with a plurality of aperture holes, the apertures of the plurality of aperture holes being unequal to each other; the main body being movably arranged so that any aperture hole can be moved to the optical axis, so that two cavities on both sides of the movable aperture are connected through the aperture hole, thereby allowing the charged particle beam to pass through the aperture hole along the direction of the optical axis.

[0006] According to an embodiment of the present application, a plurality of aperture holes are arranged in a direction perpendicular to the optical axis, the main body is movably arranged in a direction perpendicular to the optical axis, and the arrangement direction of the aperture holes is parallel to the movement direction of the main body.

[0007] According to an embodiment of the present application, the shell also includes a spacer portion, which is located between two adjacent cavities, and the main body portion is located on one side of the spacer portion along a direction parallel to the optical axis; at least one sealing ring is provided between the main body portion and the spacer portion; along the direction parallel to the optical axis, the orthographic projection of the sealing ring surrounds the orthographic projection of the aperture hole.

[0008] According to an embodiment of the present application, at least one of a side of the spacer facing the main body along the direction of the optical axis and a side of the main body facing the spacer along the direction of the optical axis is provided with a sealing groove, and at least a portion of the sealing ring is embedded in the sealing groove.

[0009] According to an embodiment of the present application, the movable aperture further includes a positioning component, which can be translated along a direction perpendicular to the optical axis; along the moving direction of the main body, the positioning component and the main body can be abutted.

[0010] According to an embodiment of the present application, the shell also includes a spacer portion, which is located between two adjacent cavities, and the main body portion is located on one side of the spacer portion along a direction parallel to the optical axis; the positioning assembly includes a positioning portion, which can be translated along a direction perpendicular to the optical axis; the positioning portion has a first positioning surface, the first positioning surface forms an acute angle with the optical axis, and the first positioning surface and the main body portion can be abutted, and / or the main body portion has a second positioning surface, the second positioning surface forms an acute angle with the optical axis, and the second positioning surface and the positioning portion can be abutted, so that the positioning portion applies a force to the main body portion to make the main body portion close to the spacer portion.

[0011] According to an embodiment of the present application, the first positioning surface is provided with a first buffer portion, and / or the second positioning surface is provided with a second buffer portion.

[0012] According to an embodiment of the present application, a first positioning surface is provided with a first roller, the axle of the first roller is perpendicular to the optical axis and to the moving direction of the main body; and / or a second positioning surface is provided with a second roller, the axle of the second roller is perpendicular to the optical axis and to the moving direction of the main body.

[0013] According to an embodiment of the present application, the cavity includes a first cavity, a second cavity and a third cavity, and the third cavity is located between the first cavity and the second cavity; a movable aperture is provided between the first cavity and the third cavity, and between the third cavity and the second cavity; the charged particle beam imaging device also includes: a beam source, a detection component and a workpiece stage; the beam source is arranged in the first cavity, and emits a charged particle beam toward the second cavity along the direction of the optical axis; the detection component is arranged in the third cavity; and the workpiece stage is arranged on the workpiece stage.

[0014] According to an embodiment of the present application, the detection assembly includes: a first detector and a second detector; the first detector has a first detection surface, and the first detection surface is perpendicular to the optical axis; the second detector has a second detection surface, and the angle between the first detection surface and the optical axis is an acute angle; and / or the charged particle beam imaging device also includes multiple vacuum pump groups, the vacuum pump groups are connected to the cavity, and the vacuum degrees of two adjacent cavities are not equal.

[0015] In the charged particle beam imaging device provided in the embodiment of the present application, the movable aperture of the charged particle beam imaging device is arranged in the housing and is located between two adjacent cavities in the housing. The main body of the movable aperture is provided with a plurality of aperture holes with different apertures. By moving the main body, any aperture hole can be moved to the optical axis of the charged particle beam imaging device of the embodiment of the present application. When a certain aperture hole is moved to the optical axis, the two cavities on both sides of the movable aperture are connected through the aperture hole, and the charged particle beam can pass through the aperture hole along the direction of the optical axis. At the same time, the vacuum difference between the two adjacent cavities is negatively correlated with the aperture of the aperture hole. Therefore, under the premise of allowing the charged particle beam to pass through the aperture hole normally, the vacuum difference between the two adjacent cavities can be adjusted by moving the aperture holes with different apertures to the optical axis, so that the charged particle beam imaging device of the embodiment of the present application can be applied to the detection of a variety of different samples to be tested, which increases the scope of application of the charged particle beam imaging device of the embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of the structure of a charged particle beam imaging device according to an embodiment of the present application.

[0018] Figure 2 A schematic structural diagram of the main body of the movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0019] Figure 3 A schematic structural diagram of a spacer and a movable aperture of a charged particle beam imaging device according to an embodiment of the present application.

[0020] Figure 4 A schematic structural diagram of the main body of the movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0021] Figure 5Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0022] Figure 6 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0023] Figure 7 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0024] Figure 8 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0025] Fig. 9 Another schematic diagram of the structure of the charged particle beam imaging device according to an embodiment of the present application.

[0026] Fig.10 Another schematic diagram of the structure of the charged particle beam imaging device according to an embodiment of the present application.

[0027] Reference numerals:

[0028] 1. Shell; 11. Cavity; 11a. First cavity; 11b. Second cavity; 11c. Third cavity; 12. Spacer;

[0029] 2. movable aperture; 21. main body; 22. aperture hole; 23. positioning assembly; 231. positioning part; 232a. first positioning surface; 232b. second positioning surface; 233a. first buffer part; 233b. second buffer part;

[0030] 31. Sealing ring; 32. Sealing groove;

[0031] 4. Beam source;

[0032] 5. Detection assembly; 51. First detector; 52. Second detector;

[0033] 6. Workpiece table;

[0034] 7. Vacuum pump set;

[0035] 8. Sample to be tested;

[0036] L. Optical axis. DETAILED DESCRIPTION

[0037] The features and exemplary embodiments of various aspects of the application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the application. However, it is obvious to those skilled in the art that the application can be implemented when some details in these specific details are not needed. The following description of the embodiments is only to provide a better understanding of the application by illustrating the example of the application.

[0038] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The embodiments will be described in detail below in conjunction with the accompanying drawings.

[0039] Relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article, or device. In the absence of further restrictions, the elements defined by the statement "comprising ..." do not exclude the presence of additional identical elements in the process, method, article, or device that includes the elements.

[0040] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Moreover, if the component is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0041] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0042] It should be understood that in the embodiment of the present application, "B corresponding to A" means that B is associated with A, and B can be determined according to A. However, it should also be understood that determining B according to A does not mean determining B only according to A, and B can also be determined according to A and / or other information.

[0043] The applicant has found that when using a charged particle beam detection and imaging device for charged particle beam detection, the charged particle beam generating part, the high charged particle beam path area and the area where the sample is located need to maintain a certain vacuum degree. Considering that the vacuum degree requirements in different areas are different, it is necessary to maintain a specific vacuum gradient between different areas. While the air is extracted by a hollow pump, a through hole with a determined aperture is also set between adjacent areas to connect the two areas, and under the premise of the aperture being determined, the vacuum degree difference between the two areas is also determined. However, since the difference in the vacuum degree of the two connected areas is related to the aperture, when the through hole is determined, the vacuum degree difference of the two connected areas is also determined. For different samples to be tested, the demand for vacuum gradient is also different, so it is necessary to design a charged particle beam detection and imaging device according to different vacuum gradient requirements, and the aperture of the through hole will often limit the use of the charged particle beam source. Therefore, the finished product of the charged particle beam detection and imaging device has a limited scope of application.

[0044] In view of the above analysis, the applicant proposes a charged particle beam imaging device, including a shell with multiple cavities and a movable aperture. The movable aperture is arranged in the shell and is located between two adjacent cavities in the shell. The main body of the movable aperture is provided with multiple aperture holes with different apertures. By moving the main body, any aperture hole can be moved to the optical axis of the charged particle beam imaging device of the embodiment of the present application. When a certain aperture hole is moved to the optical axis, the two cavities on both sides of the movable aperture are connected through the aperture hole, and the charged particle beam can pass through the aperture hole along the direction of the optical axis. At the same time, the vacuum difference between the two adjacent cavities is negatively correlated with the aperture of the aperture hole. Therefore, under the premise of allowing the charged particle beam to pass through the aperture hole normally, the vacuum difference between the two adjacent cavities can be adjusted by moving the aperture holes with different apertures to the optical axis, so that the charged particle beam imaging device of the embodiment of the present application can be applied to the detection of a variety of different samples to be tested, which increases the scope of application of the charged particle beam imaging device of the embodiment of the present application.

[0045] Figure 1 A schematic diagram of the structure of a charged particle beam imaging device according to an embodiment of the present application. Figure 2 A schematic structural diagram of the main body of the movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0046] See also Figure 1 and Figure 2The embodiment of the present application provides a charged particle beam imaging device, comprising: a housing 1 and a movable aperture 2. The housing 1 comprises a plurality of cavities 11, and the plurality of cavities 11 are connected along a direction parallel to the optical axis L of the charged particle beam imaging device; the movable aperture 2 is arranged in the housing 1 and is located between two adjacent cavities 11, and the movable aperture 2 comprises a main body 21, and the main body 21 is provided with a plurality of aperture holes 22, and the apertures of the plurality of aperture holes 22 are not equal to each other; the main body 21 is movably arranged so that any aperture hole 22 can be moved to the optical axis L, so that the two cavities 11 on both sides of the movable aperture 2 are connected through the aperture hole 22, thereby allowing the charged particle beam to pass through the aperture hole 22 along the direction of the optical axis L.

[0047] In the embodiment of the present application, the charged particle beam is emitted in the direction of the optical axis L, and the housing 1 may be a body of revolution with the optical axis L as the axis, or may not be a body of revolution with the optical axis L as the axis. It should be emphasized that other optical devices of the charged particle beam imaging device of the embodiment of the present application should be installed with the optical axis L as the reference and need to be aligned with the optical axis L.

[0048] The housing 1 is used to protect other components of the charged particle beam imaging device of the embodiment of the present application. The interior of the housing 1 is hollow and forms a plurality of cavities 11 to accommodate various components, such as an electron gun, a lens, an objective lens and other optical devices that emit electron beams. According to the requirements of the sample 8 under test for the vacuum degree of each cavity 11, the vacuum degree of each cavity 11 may be different, that is, there is a difference in vacuum gradient.

[0049] The movable aperture 2 is arranged between two adjacent cavities 11, and a main body 21 of the movable aperture 2 is provided with a plurality of aperture holes 22. The main body 21 can be moved, and any aperture hole 22 on the main body 21 can be moved to the optical axis L by moving the main body 21. When a certain aperture hole 22 moves to the optical axis L with the main body 21, the two adjacent cavities 11 are connected through the aperture hole 22 of the movable aperture 2, and the charged particle beam can be injected from one cavity 11 into the other cavity 11 through the aperture hole 22 along the direction of the optical axis L. Exemplarily, the main body 21 of the movable aperture 2 can be driven to move by a motor, a telescopic cylinder, or the like.

[0050] The aperture 22 may be in a truncated cone shape, and the aperture of the aperture 22 gradually increases along the optical axis L. The gas transmittance (leakage rate) is proportional to the aperture of the aperture 22 and inversely proportional to the hole depth of the aperture 22. In addition, the air pressure difference on both sides of the aperture 22 is negatively correlated with the leakage rate, so the difference in the vacuum degree of two adjacent cavities 11 is positively correlated with the aperture of the aperture 22 and the hole depth of the aperture 22. For ease of understanding, the aperture of the aperture 22 mentioned in the embodiment of the present application refers to the minimum value of the aperture in the aperture 22. In the embodiment of the present application, the hole depth of each aperture 22 is equal as an example for explanation. At this time, the difference in the vacuum degree of two adjacent cavities 11 is negatively correlated with the aperture of the aperture 22, but the hole depths of each aperture 22 of the movable aperture 2 in the embodiment of the present application may not be equal.

[0051] Since the two adjacent cavities 11 are connected through the aperture hole 22, the positive emptyness difference between the two cavities 11 is negatively correlated with the aperture of the aperture hole 22. Considering that the movable main body 21 can move the aperture holes 22 of different apertures to the optical axis L, the difference in vacuum between the two cavities 11 corresponds to different values. Therefore, when using the charged particle beam imaging device of the embodiment of the present application, the aperture holes 22 of different apertures can be moved to the optical axis L by moving the main body 21, so that the vacuum difference corresponding to the aperture of the aperture hole 22 can be generated between the two adjacent cavities 11, so as to meet the vacuum requirements of each cavity 11 in different detection scenarios, and in the process of adjusting the vacuum, the operation is simple, which can simplify the installation and adjustment process of the charged particle beam imaging device of the embodiment of the present application, and increase the scope of application of the charged particle beam imaging device of the embodiment of the present application.

[0052] Further, see Figure 2 A plurality of aperture holes 22 are arranged in a direction perpendicular to the optical axis L, the main body 21 is movably arranged in a direction perpendicular to the optical axis L, and the arrangement direction of the aperture holes 22 is parallel to the movement direction of the main body 21 .

[0053] When one aperture hole 22 is located at the optical axis L, the main body 21 translates in a direction perpendicular to the optical axis L, so that another aperture hole 22 moves to the optical axis L. Considering that the plurality of aperture holes 22 are arranged in a direction perpendicular to the optical axis L, the main body 21 can move quickly in a shorter path to achieve the switching of aperture holes 22 with different apertures at the optical axis L, shortening the movement distance of the main body 21, reducing the control difficulty of the movement of the main body 21, and reducing the space occupied by the movable aperture 2 in the housing 1.

[0054] Figure 3 A schematic structural diagram of a spacer and a movable aperture of a charged particle beam imaging device according to an embodiment of the present application. Figure 4A schematic structural diagram of the main body of the movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0055] For further information, see Figure 3 and Figure 4 The shell 1 also includes a spacer 12, which is located between two adjacent cavities 11, and the main body 21 is located on one side of the spacer 12 along a direction parallel to the optical axis L; at least one sealing ring 31 is provided between the main body 21 and the spacer 12; along the direction parallel to the optical axis L, the orthographic projection of the sealing ring 31 surrounds the orthographic projection of the aperture hole 22.

[0056] The interior of the shell 1 is hollow, and the spacer 12 divides the hollow area into a plurality of cavities 11. The main body of the movable aperture 2 is arranged on one side of the spacer 12. At the position of the optical axis L, the spacer 12 is provided with a through hole. When the main body moves relative to the spacer 12 until a certain aperture hole 22 is aligned with the through hole, that is, the aperture hole 22 moves to the optical axis L, the charged particle beam can enter another cavity 11 from one cavity 11 through the aperture hole 22 and the through hole along the optical axis L. Considering that the aperture of the through hole can be larger than the aperture of the aperture hole 22, the diameter of the airflow passage between the two cavities 11 is the aperture of the aperture hole 22. At least one sealing ring 31 is provided between the main body 21 and the spacer 12. The sealing ring 31 can seal the gap between the main body 21 and the spacer 12, so that the airflow flowing through the two cavities 11 can only flow through the aperture 22, so that the parameters of the aperture 22 determine the flow rate of the airflow. Under the premise that the thickness of the main body is determined, the aperture of the aperture 22 determines the difference in vacuum degree between the two cavities 11.

[0057] Further, see Figure 3 and Figure 4 , the side of the spacer 12 facing the main body 21 along the direction of the optical axis L, and the side of the main body 21 facing the spacer 12 along the direction of the optical axis L, that is, the two surfaces of the spacer 12 and the main body 21 close to each other. At least one of the two surfaces is provided with a sealing groove 32, and at least a part of the sealing ring 31 is embedded in the sealing groove 32, so as to reduce the risk of the sealing ring 31 rolling, so that the sealing ring 31 can always seal the area around the through hole of the spacer 12 and the main body 21, and then the aperture of the aperture 22 located at the optical axis L determines the difference in vacuum between the two cavities 11.

[0058] Figure 5 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0059] For further information, see Figure 5The movable aperture 2 further includes a positioning assembly 23 , which can be translated along a direction perpendicular to the optical axis L; along the moving direction of the main body 21 , the positioning assembly 23 and the main body 21 can be abutted against each other.

[0060] The positioning assembly 23 is used to limit the movement of the main body 21, so as to fix the relative position of the main body 21 and the spacer 12. The positioning assembly 23 can move in a direction perpendicular to the optical axis L. When the positioning assembly 23 moves to a certain preset position and fixes the relative position of the positioning assembly 23 and the spacer 12, the main body 21 is moved again until the main body 21 abuts against the positioning assembly 23. At this time, the phase position of the main body 21 and the spacer 12 can be regarded as fixed, and at the same time, a certain aperture hole 22 is located at the optical axis L.

[0061] Figure 6 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0062] For further information, see Figure 6 The shell 1 also includes a spacer 12, which is located between two adjacent cavities 11, and the main body 21 is located on one side of the spacer 12 along a direction parallel to the optical axis L; the positioning assembly 23 includes a positioning portion 231, which can be translated along a direction perpendicular to the optical axis L; the positioning portion 231 has a first positioning surface 232a, and the angle between the first positioning surface 232a and the optical axis L is acute, and the first positioning surface 232a and the main body 21 can be abutted, and / or the main body 21 has a second positioning surface 232b, and the angle between the second positioning surface 232b and the optical axis L is acute, and the second positioning surface 232b and the positioning portion 231 can be abutted, so that the positioning portion 231 applies a force to the main body 21 so that the main body 21 is tightly against the spacer 12.

[0063] The main body is located on one side of the spacer 12. When the positioning portion 231 of the positioning assembly 23 abuts against the main body, the positioning portion 231 can apply a force to the main body to press the main body against the spacer 12, thereby improving the sealing effect between the main body and the spacer 12 and ensuring airtightness. Considering that the positioning portion 231 presses the main body against the spacer 12, when the force applied by the positioning portion 231 to the main body is decomposed in the direction parallel to the optical axis L and in the direction perpendicular to the optical axis L, the force component in the direction parallel to the optical axis L is directed toward the spacer 12. At the abutment between the positioning portion 231 and the main body 21, at least one of the positioning portion 231 and the main body 21 can be provided with a surface inclined relative to the optical axis L. When the positioning portion 231 and the main body 21 abut, the force applied by the inclined surface is perpendicular to the surface, so the component of the force in the direction parallel to the optical axis L is directed toward the spacer 12. Specifically, the positioning portion 231 has a first positioning surface 232a, the angle between the first positioning surface 232a and the optical axis L is acute, and the first positioning surface 232a and the main body 21 can be abutted, and / or the main body 21 has a second positioning surface 232b, the angle between the second positioning surface 232b and the optical axis L is acute, and the second positioning surface 232b and the positioning portion 231 can be abutted.

[0064] Figure 7 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application. Figure 8 Another structural schematic diagram of the spacer and movable aperture of the charged particle beam imaging device according to an embodiment of the present application.

[0065] For further information, see Figure 7 and Figure 8 The first positioning surface 232a is provided with a first buffer portion 233a, and / or the second positioning surface 232b is provided with a second buffer portion 233b. Taking the first buffer portion 233a as an example, when the positioning portion 231 and the main body 21 abut, the first buffer portion 233a can reduce the vibration and deformation generated when the positioning portion 231 and the main body 21 abut, thereby reducing the risk of deformation or even damage to the positioning portion 231 and the main body 21. The structure of the second buffer portion 233b can be consistent with that of the first buffer portion 233a, and will not be repeated.

[0066] Further, see Figure 7 and Figure 8 The first positioning surface 232a is provided with a first roller, the axle of the first roller is perpendicular to the optical axis L and perpendicular to the moving direction of the main body 21; and / or the second positioning surface 232b is provided with a second roller, the axle of the second roller is perpendicular to the optical axis L and perpendicular to the moving direction of the main body 21.

[0067] The first buffer portion 233a and the second buffer portion 233b are in the form of rollers. The first roller corresponds to the first buffer portion 233a, and the second roller corresponds to the second buffer portion 233b. Taking the first roller as an example, the axle of the first roller is perpendicular to the optical axis L and perpendicular to the moving direction of the main body 21. When relative displacement occurs between the spacer 12 and the main body 21, the first roller can generate a rolling tendency, thereby achieving the purpose of buffering. The structure of the second roller is consistent with that of the first roller, and will not be repeated.

[0068] Fig. 9 Another schematic diagram of the structure of the charged particle beam imaging device according to an embodiment of the present application.

[0069] For further information, see Fig. 9 The cavity 11 includes a first cavity 11a, a second cavity 11b and a third cavity 11c, and the third cavity 11c is located between the first cavity 11a and the second cavity 11b; a movable aperture 2 is provided between the first cavity 11a and the third cavity 11c, and between the third cavity 11c and the second cavity 11b; the charged particle beam imaging device also includes: a beam source 4, a detection component 5 and a workpiece stage 6; the beam source 4 is arranged in the first cavity 11a, and emits a charged particle beam toward the second cavity 11b along the direction of the optical axis L; the detection component 5 is arranged in the third cavity 11c; the workpiece stage 6 is arranged on the workpiece stage 6.

[0070] In the embodiment of the present application, a built-in beam source 4 is used, that is, a beam source 4 is provided in the shell 1. It is understandable that an external beam source 4 can also be used to introduce the charged particle beam along the optical axis L into the charged particle beam imaging device of the embodiment of the present application.

[0071] Fig.10 Another schematic diagram of the structure of the charged particle beam imaging device according to an embodiment of the present application.

[0072] In the present application, please refer to Fig.10 , the multiple cavities 11 include a first cavity 11a, a second cavity 11b and a third cavity 11c. The beam source 4 of the charged particle beam can be arranged in the first cavity 11a, and the charged particle beam is emitted along the optical axis L, passes through the third cavity 11c, and is emitted to the sample 8 under test in the second cavity 11b. The number of the third cavity 11c can be multiple, and the adjacent first cavity 11a and the third cavity 11c, the adjacent two third cavities 11c, and the adjacent third cavity 11c and the second cavity 11b are all connected through the movable aperture 2.

[0073] The first focusing lens is also disposed in the first cavity 11a and is located on the side of the beam source 4 close to the second cavity 11b along the direction of the optical axis L. The charged particle beam can pass through the first focusing lens and converge to a certain extent. The first centering device is also disposed in the first cavity 11a and is located on the side of the beam source 4 close to the second cavity 11b along the direction of the optical axis L. The charged particle beam can pass through the first centering device, so that the charged particle beam can be centered while converging, that is, the axis of the charged particle beam coincides with the optical axis L.

[0074] Taking the number of the third cavity 11c as two as an example, the third cavity 11c includes a first sub-cavity and a second sub-cavity, and the first cavity 11a, the first sub-cavity, the second sub-cavity and the second cavity 11b are connected in sequence along the direction of the optical axis L.

[0075] The second focusing lens is arranged in the first sub-cavity and is located on the side of the beam source 4 close to the second cavity 11b along the direction of the optical axis L. The charged particle beam can pass through the second focusing lens and converge to a certain extent. The second centering device is also arranged in the first sub-cavity and is located on the side of the beam source 4 close to the second cavity 11b along the direction of the optical axis L. The charged particle beam can pass through the second centering device, so that the charged particle beam can be centered while converging. The anti-stigmation device is arranged in the first sub-cavity and is located on the side of the second centering device close to the second sub-cavity along the direction of the optical axis L, which can weaken the astigmatism generated by the charged particle beam after centering and converging. The beam gate is arranged in the first sub-cavity and is located on the side of the anti-stigmation device close to the second sub-cavity along the direction of the optical axis L. It can effectively and quickly cut off the charged particle beam during the exposure process, thereby improving the accuracy of detection.

[0076] The objective lens is arranged in the second sub-cavity, and can focus the charged particle beam on the surface of the sample 8 to be tested, so that the obtained image can truly reflect the surface characteristics of the sample 8 to be tested. The deflector is arranged in the second sub-cavity, and is located on the side of the objective lens close to the second cavity 11b along the direction of the optical axis L, and can deflect the charged particle beam so that the charged particle beam can scan the surface of the sample 8 to be tested. The detection component 5 is arranged in the second sub-cavity. When the charged particle beam is reflected and / or scattered on the surface of the sample 8 to be tested, the detection component 5 can detect the reflected and / or scattered charged particle beam to obtain the detection result, and it can be judged whether the sample 8 to be tested has defects according to the detection result.

[0077] The work stage 6 is arranged in the second cavity 11b, and the sample 8 to be tested is placed on the work stage 6. The work stage 6 can provide stable support for the sample to be tested, so that after the sample 8 to be tested reflects the charged particle beam, the image obtained can reflect the surface characteristics of the sample 8 to be tested.

[0078] Further, see Fig.10The detection assembly 5 includes: a first detector 51 and a second detector 52; the first detector 51 has a first detection surface, and the first detection surface is perpendicular to the optical axis L; the second detector 52 has a second detection surface, and the angle between the first detection surface and the optical axis L is an acute angle.

[0079] The first detector 51 is disposed in the second sub-cavity and is located on the side of the objective lens away from the second cavity 11b along the direction of the optical axis L. The first detection surface of the first detector 51 is perpendicular to the optical axis L. After the charged particle beam is reflected on the surface of the sample 8, the first detector 51 can detect the reflected charged particles.

[0080] The second detector 52 is disposed in the second sub-cavity and is located on the side of the objective lens away from the second cavity 11b along the direction of the optical axis L. The second detection surface of the second detector 52 forms an acute angle with the optical axis L. After the charged particle beam is reflected on the surface of the sample 8, the second detector 52 can detect the scattered charged particles.

[0081] Furthermore, the charged particle beam imaging device further comprises a plurality of vacuum pump groups 7 , the vacuum pump groups 7 are connected to the cavities 11 , and the vacuum degrees of two adjacent cavities 11 are not equal.

[0082] The vacuum pump group 7 can pump air out of the corresponding cavity 11 to meet the vacuum degree requirement, and can make the adjacent cavity 11 meet the vacuum gradient requirement in combination with the movable aperture 2. Exemplarily, the vacuum pump group 7 connected to the first cavity 11a can be in the form of an ion pump; the vacuum pump group 7 connected to the second cavity 11b can be in the form of a combination of a molecular pump and a mechanical pump; the vacuum pump group 7 connected to the third cavity 11c can be in the form of a molecular pump or an ion pump.

[0083] Considering that a plurality of different optical devices may be arranged in the third cavity 11c, the corresponding vacuum requirements may be different. The third cavity 11c may include a first sub-cavity and a second sub-cavity. The vacuum degree of the first sub-cavity and the vacuum degree of the second sub-cavity are not equal to each other, so as to meet the vacuum requirements of different optical devices. It is understandable that the vacuum degrees of the first cavity 11a, the first sub-cavity, the second sub-cavity and the second cavity 11b may not be all the same, or may be all different. For example, the vacuum degree of the first cavity 11a may be less than 5e-9 Torr (5×10 -9 Torr, the vacuum degree of the first sub-chamber can be 5e-8Torr (5×10 -8 Torr) to 5e-9 Torr (5×10 -9 Torr); the vacuum degree of the second sub-chamber can be 5e-8 Torr (5×10 -8 Torr) to 1e-7 Torr (1×10 -7Torr); the vacuum degree of the second cavity 11b can be 1e-6 Torr (1×10 - 6 The first sub-cavity and the second sub-cavity are connected through the third aperture of the movable aperture 2.

[0084] In summary, the embodiment of the present application provides a charged particle beam imaging device, wherein the movable aperture of the charged particle beam imaging device is arranged in a housing and is located between two adjacent cavities in the housing. The main body of the movable aperture is provided with a plurality of aperture holes with different apertures, and any aperture hole can be moved to the optical axis of the charged particle beam imaging device of the embodiment of the present application by moving the main body. When a certain aperture hole is moved to the optical axis, the two cavities on both sides of the movable aperture are connected through the aperture hole, and the charged particle beam can pass through the aperture hole along the direction of the optical axis. At the same time, the vacuum difference between the two adjacent cavities is negatively correlated with the aperture of the aperture hole. Therefore, under the premise of allowing the charged particle beam to pass through the aperture hole normally, the vacuum difference between the two adjacent cavities can be adjusted by moving the aperture holes of different apertures to the optical axis, so that the charged particle beam imaging device of the embodiment of the present application can be applied to the detection of a variety of different samples to be tested, thereby increasing the scope of application of the charged particle beam imaging device of the embodiment of the present application.

[0085] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A charged particle beam imaging device, characterized in that: include: A housing, comprising a plurality of cavities, wherein the plurality of cavities are connected along a direction parallel to an optical axis of the charged particle beam imaging device; A movable aperture is arranged in the housing and located between two adjacent cavities, the movable aperture comprises a main body, the main body is provided with a plurality of aperture holes, and the apertures of the plurality of aperture holes are not equal to each other; the main body is movably arranged so that any of the aperture holes can be moved to the optical axis, so that the two cavities on both sides of the movable aperture are connected through the aperture hole, thereby allowing the charged particle beam to pass through the aperture hole along the direction of the optical axis, and enabling a vacuum degree difference corresponding to the aperture of the aperture hole to be generated between the two adjacent cavities; The plurality of aperture holes are arranged in a direction perpendicular to the optical axis, the main body is arranged to be movably arranged in a direction perpendicular to the optical axis, and the arrangement direction of the aperture holes is parallel to the movement direction of the main body; The movable aperture further comprises a positioning assembly, and the positioning assembly can be arranged to be translated along a direction perpendicular to the optical axis; along the moving direction of the main body, the positioning assembly and the main body can be arranged to abut against each other.

2. The charged particle beam imaging device according to claim 1, characterized in that: The housing further comprises a spacer, the spacer is located between two adjacent cavities, and the main body is located on one side of the spacer along a direction parallel to the optical axis; At least one sealing ring is provided between the main body and the spacer; Along a direction parallel to the optical axis, the orthographic projection of the sealing ring surrounds the orthographic projection of the aperture.

3. The charged particle beam imaging device according to claim 2, characterized in that: At least one of the side of the spacer facing the main body along the direction of the optical axis and the side of the main body facing the spacer along the direction of the optical axis is provided with a sealing groove, and at least a portion of the sealing ring is embedded in the sealing groove.

4. The charged particle beam imaging device according to claim 1, characterized in that: The housing further comprises a spacer, the spacer is located between two adjacent cavities, and the main body is located on one side of the spacer along a direction parallel to the optical axis; The positioning assembly comprises a positioning portion, and the positioning portion is arranged to be translationally movable along a direction perpendicular to the optical axis; The positioning portion has a first positioning surface, the angle between the first positioning surface and the optical axis is acute, and the first positioning surface can be abutted against the main body, and / or the main body has a second positioning surface, the angle between the second positioning surface and the optical axis is acute, and the second positioning surface can be abutted against the positioning portion, so that the positioning portion applies a force to the main body to make the main body close to the spacing portion.

5. The charged particle beam imaging device according to claim 4, characterized in that: The first positioning surface is provided with a first buffer portion, and / or the second positioning surface is provided with a second buffer portion.

6. The charged particle beam imaging device according to claim 4, characterized in that: The first positioning surface is provided with a first roller, and the axle of the first roller is perpendicular to the optical axis and perpendicular to the moving direction of the main body; And / or, the second positioning surface is provided with a second roller, and the axle of the second roller is perpendicular to the optical axis and perpendicular to the moving direction of the main body.

7. The charged particle beam imaging device according to claim 1, characterized in that: The cavity comprises a first cavity, a second cavity and a third cavity, wherein the third cavity is located between the first cavity and the second cavity; the movable aperture is provided between the first cavity and the third cavity, and between the third cavity and the second cavity; The charged particle beam imaging device further comprises: a beam source, a detection assembly and a workpiece stage; the beam source is arranged in the first cavity, and emits a charged particle beam toward the second cavity along the direction of the optical axis; The detection component is arranged in the third cavity; and the workpiece table is arranged on the workpiece table.

8. The charged particle beam imaging device according to claim 7, characterized in that: The detection assembly comprises: a first detector and a second detector; The first detector has a first detection surface, and the first detection surface is perpendicular to the optical axis; The second detector has a second detection surface, and the angle between the first detection surface and the optical axis is acute; And / or, the charged particle beam imaging device further comprises a plurality of vacuum pump groups, wherein the vacuum pump groups are connected to the cavities, and the vacuum degrees of two adjacent cavities are not equal.

Images