Backscattered electron detector and scanning electron microscope

Abstract

This application provides a backscattered electron detection device and a scanning electron microscope (SEM). In the SEM, the sample stage, microscope tube, secondary electron detection device, and backscattered electron detection device are all disposed in the sample chamber. The backscattered electron detection device includes a movable support and a detection unit. The movable support is mounted in the sample chamber, and the detection unit is connected to the movable support. The detection unit includes a detector element. At least a portion of the movable support is rotatable relative to the sample chamber, allowing the detection unit to move between a clearance position and a detection position. When the detection unit is in the detection position, the detector element is located on the line connecting the sample stage and the microscope tube; when the detection unit is in the clearance position, the detector element is away from the line connecting the sample stage and the microscope tube. When the secondary electron detection device is working, the backscattered electron detection device of this application rotates to avoid secondary electrons emitted from the sample. Furthermore, it can optimize the working distance during the detection process.

Description

Technical Field

[0001] This application relates to scanning electron microscopy technology, specifically to a backscattered electron detection device and a scanning electron microscope. Background Technology

[0002] Scanning electron microscopy (SEM) is an instrument that uses a high-energy electron beam to scan the surface of a sample and obtain high-resolution microscopic images by detecting the electron signals. It has wide applications in materials science, biology, semiconductors, and nanotechnology. SEM collects electron signals using different types of detectors, such as secondary electron detectors and backscattered electron detectors. Backscattered electron detectors are used to detect backscattered electrons with large scattering angles and high energy; therefore, they are generally positioned below the microscope tube, between the sample and the tube. Secondary electron detectors are used to detect lower-energy secondary electrons. These detectors are typically positioned to the side and above the sample. To capture more secondary electrons, an electric field is usually placed at the tip of the secondary electron detector to attract them. After secondary electrons form on the sample surface, they are deflected towards the detector under the influence of the electric field.

[0003] However, because the backscattered electron probe is close to the sample, such as Figure 1 As shown, some secondary electrons are easily blocked by the backscattered electron probe during their deflection to the secondary electron probe, thus affecting the quality of the secondary electron imaging. Furthermore, to optimize the working distance during the detection process, it is sometimes necessary to adjust the height of the sample stage. However, the backscattered electron probe positioned between the sample and the microscope tube can sometimes restrict the vertical movement of the sample stage, thereby affecting the imaging quality. Utility Model Content

[0004] This application provides a backscattered electron detection device and a scanning electron microscope. When the secondary electron detection device is working, the backscattered electron detection device avoids the secondary electrons emitted from the sample by rotating. In addition, it can also optimize the working distance during the detection process.

[0005] One embodiment of this application provides a scanning electron microscope, including: a sample chamber with a sample stage for placing a sample; a microscope tube disposed in the sample chamber and spaced apart from the sample stage for emitting an electron beam; a secondary electron detection device disposed in the sample chamber for detecting secondary electrons generated by the sample; and a backscattered electron detection device disposed in the sample chamber, the backscattered electron detection device including a movable support and a detection part, the movable support being mounted in the sample chamber and the detection part being connected to the movable support, the detection part including a detector element for detecting backscattered electrons; at least a portion of the movable support is rotatable relative to the sample chamber, so that the detection part moves between a clearance position and a detection position; when the detection part is in the detection position, the detector element is located on the line connecting the sample stage and the microscope tube; when the detection part is in the clearance position, the detector element is away from the position of the line connecting the sample stage and the microscope tube.

[0006] In one embodiment, the height of the movable support within the sample chamber is higher than that of the detector; the movable support includes a fixing member and a rotating member, the fixing member is fixed to the side wall of the sample chamber, the rotating member is rotatably connected to the fixing member, and the detector is connected to the rotating member; the fixing member, the rotating member, and the detector are arranged from top to bottom within the sample chamber.

[0007] In one embodiment, the fixing member includes an installation end and a connecting end disposed opposite to each other. The installation end is connected to the side wall of the sample chamber, and the connecting end is rotatably connected to the rotating member. When the detection part is located in the detection position, the rotating member protrudes from the connecting end in a direction away from the installation end, and the detection part protrudes from the rotating member in a direction away from the connecting end.

[0008] In one embodiment, the fixing member is provided with a positioning structure, which is used to position the rotating member when the detection part is in the detection position.

[0009] In one embodiment, the fixing member is further provided with a first fixing structure, and the rotating member is provided with a second fixing structure. When the detection part is in the avoidance position, the first fixing structure and the second fixing structure cooperate to fix the detection part in the avoidance position.

[0010] In one embodiment, the fixing member is provided with a first connecting structure, and the rotating member is provided with a second connecting structure. The second connecting structure is rotatably connected to the first connecting structure so that the rotating member can rotate relative to the fixing member.

[0011] In one embodiment, the fixing member is further provided with a third connecting structure, and the rotating member is provided with a fourth connecting structure; when the detection part rotates to the detection position, the fourth connecting structure connects with the third connecting structure to fix the detection part at the detection position.

[0012] In one embodiment, the fixing member is further provided with a third connecting structure, and the rotating member is provided with a fourth connecting structure. The third connecting structure is a through hole or a groove, and the fourth connecting structure is a top bead. The top bead has an upper end and a lower end, and the top bead passes through the rotating member in a vertical direction. The top bead and the rotating member are connected by a spring, so that the top bead tends to protrude upward under the action of the spring. The upper end protrudes from the upper surface of the rotating member, and the lower end protrudes from the lower surface of the rotating member.

[0013] In one embodiment, the rotation angle of the movable support is 60°-180°.

[0014] One embodiment of this application provides a backscattered electron detection device, comprising: a movable support for connection to a sample chamber; and a detection unit connected to the movable support, the detection unit including a detector element for detecting backscattered electrons; at least a portion of the movable support is rotatable relative to the sample chamber to allow the detection unit to move between a clearance position and a detection position; when the detection unit is in the detection position, the detector element is located on the line connecting the sample stage and the mirror barrel; when the detection unit is in the clearance position, the detector element is moved away from the line connecting the sample stage and the mirror barrel.

[0015] This application provides a backscattered electron detection device and a scanning electron microscope. The backscattered electron detection device includes a movable support and a detection unit, which are connected to the movable support. The movable support is installed in the sample chamber, and at least a portion of the movable support is rotatable relative to the sample chamber, allowing the detection unit to move between a clearance position and a detection position. Since secondary electron imaging and backscattered electron imaging of the sample are independent, when a secondary electron probe is needed to detect secondary electrons in the sample, the movable support can be rotated relative to the sample chamber, causing the detection unit to move to the clearance position. This moves the detector away from the line connecting the sample stage and the microscope tube, preventing the backscattered electron device from obstructing the movement of secondary electrons and improving the secondary electron imaging quality. When the backscattered electron device is needed to detect backscattered electrons in the sample, the movable support can be rotated relative to the sample chamber, causing the detection unit to move to the detection position, allowing the detector to detect the backscattered electrons. Furthermore, when optimizing the working distance during the detection process, this can also be achieved by rotating the movable support, preventing the detector from limiting the vertical adjustment height of the sample stage and further improving imaging quality. Attached Figure Description

[0016] Figure 1 A perspective view of a scanning electron microscope in the prior art;

[0017] Figure 2 This is a schematic diagram of the structure of a scanning electron microscope in one embodiment of this application;

[0018] Figure 3 This is a perspective view of a scanning electron microscope in one embodiment of this application;

[0019] Figure 4 This is a three-dimensional structural schematic diagram of a backscattered electron detection device in one embodiment of this application, where the detection unit is located at the detection position;

[0020] Figure 5 A three-dimensional structural schematic diagram of a backscattered electron detection device in one embodiment of this application, wherein the detection part is located in the avoidance position;

[0021] Figure 6 for Figure 4 The rear view of the backscattered electron detector shown.

[0022] Reference numerals: Scanning electron microscope-100, sample chamber-110, sample stage-111, microscope tube-120, secondary electron detector-130, backscattered electron detector-140, movable support-141, fixing component-142, mounting end-1421, connecting end-1422, positioning structure-1423, first connecting structure-1424, third connecting structure-1425, rotating component-143, second connecting structure-1431, fourth connecting structure-1432, detector-144. Detailed Implementation

[0023] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0024] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments, and the operational steps involved in each embodiment can also be rearranged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the specification and drawings are only for clearly describing a particular embodiment and do not imply that they represent the necessary components and / or order.

[0025] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0026] This application provides a scanning electron microscope 100, please refer to... Figure 2-6 The scanning electron microscope 100 includes a sample chamber 110, a microscope tube 120, a secondary electron detection device 130, and a backscattered electron detection device 140.

[0027] Please refer to Figure 3 The sample chamber 110 is equipped with a sample stage 111 for placing samples. A microscope tube 120 is disposed in the sample chamber 110 and spaced apart from the sample stage 111, for emitting an electron beam. A secondary electron detection device 130 is disposed in the sample chamber 110 for detecting secondary electrons generated by the sample. A backscattered electron detection device 140 is disposed in the sample chamber 110, including a movable support 141 and a detection unit 144. The movable support 141 is mounted on the sample chamber 110, and the detection unit 144 is connected to the movable support 141. The detection unit 144 includes a detector element (not shown) for detecting backscattered electrons. At least a portion of the movable support 141 is rotatable relative to the sample chamber 110, allowing the detection unit 144 to move between a clearance position and a detection position. Figure 3-5 As shown, when the detector 144 is in the detector position, the detector element is located on the line connecting the sample stage 111 and the lens barrel 120; when the detector 144 is in the clearance position, the detector element is away from the line connecting the sample stage 111 and the lens barrel 120.

[0028] The backscattered electron detection device 140 of this application includes a movable support 141 and a detection unit 144. The movable support 141 is connected to the detection unit 144 and to the sample chamber 110. At least a portion of the movable support 141 is rotatable relative to the sample chamber 110, allowing the detection unit 144 to move between a clearance position and a detection position. Since secondary electron imaging and backscattered electron imaging of the sample are independent, when it is necessary to use a secondary electron probe to detect secondary electrons in the sample, the movable support 141 can be rotated relative to the sample chamber 110, causing the detection unit 144 to move to the clearance position. The detector then moves away from the line connecting the sample stage 111 and the microscope tube 120, thus preventing the backscattered electron detection device 140 from obstructing the movement of secondary electrons and improving the secondary electron imaging quality. When it is necessary to use the backscattered electron detection device 140 to detect backscattered electrons in the sample, the movable support 141 can be rotated relative to the sample chamber 110, causing the detection unit 144 to move to the detection position, whereby the detector can then detect the backscattered electrons. Meanwhile, the rotatable arrangement of the movable support 141 relative to the sample chamber 110 can release the space between the sample stage 111 and the microscope tube 120, thereby relaxing the restrictions on sample size, or expanding the range of motion of the sample stage 111 in the vertical direction, thereby optimizing the working distance and further improving the imaging quality.

[0029] like Figure 3 As shown, the sample stage 111 is positioned opposite to the microscope tube 120, and the secondary electron detection device 130 and the backscattered electron detection device 140 are positioned on the two opposite side walls of the sample chamber 110.

[0030] Please refer to Figure 3 The movable support 141 is positioned higher than the detector 144 within the sample chamber 110. This arrangement allows the movable support 141 to avoid the detector position to a certain extent.

[0031] Please refer to Figure 3-4 The movable support 141 includes a fixing member 142 and a rotating member 143. The fixing member 142 is fixed to the side wall of the sample chamber 110. The rotating member 143 is rotatably connected to the fixing member 142. The detection member 144 is connected to the rotating member 143. The fixing member 142, the rotating member 143 and the detection member 144 are arranged from top to bottom in the sample chamber 110.

[0032] Similarly, by arranging the fixing member 142, the rotating member 143, and the detection unit 144 from top to bottom within the sample chamber 110, the structure defined by the fixing member 142, the rotating member 143, and the detection unit 144 themselves can form a clearance space, thereby achieving clearance of the detection position.

[0033] Please refer to Figure 4The fixing member 142 includes a mounting end 1421 and a connecting end 1422 disposed opposite to each other. The mounting end 1421 is connected to the side wall of the sample chamber 110, and the connecting end 1422 is rotatably connected to the rotating member 143. When the detection part 144 is in the detection position, the rotating member 143 protrudes from the connecting end 1422 in a direction away from the mounting end 1421, and the detection part 144 protrudes from the rotating member 143 in a direction away from the connecting end 1422.

[0034] More intuitively, such as Figure 4 As shown in the diagram, when the detector 144 is in the detection position, the line connecting the fixing member 142, the rotating member 143, and the detector 144 is tilted. This design also creates clearance space within the backscattered electron detection device 140 itself. Figure 4 As shown, the fixing member 142, the rotating member 143, and the detection unit 144 all have inclined surfaces that mate with the conical objective lens at the bottom of the lens barrel 120. This allows the backscattered electron detection device 140 to avoid the lens barrel 120 and be positioned at a higher position, thereby reducing the influence of the backscattered electron detection device 140 on the secondary electron detection device 130. More specifically, as Figure 3 The fixing member 142 and the rotating member 143 are at the same height as a part of the lens barrel 120. When the detection part 144 is in the detection position, the fixing member 142 and the rotating member 143 still avoid the detection position, and only the detection part 144 extends into the detection position.

[0035] In other embodiments, the detection part 144 may simply protrude from the rotating member 143, while the rotating member 143 remains housed in the lower space of the fixing member 142.

[0036] Please refer to Figure 6 The fixing member 142 is provided with a positioning structure 1423. When the detection part 144 is located in the detection position, the positioning structure 1423 is used to position the rotating member 143.

[0037] When the probe is rotated to the detection position by the self-avoidance mechanism, the positioning structure 1423 ensures that the probe is accurately positioned. In one embodiment of this application, the positioning structure 1423 can be a baffle disposed on the fixing member 142. When the probe 144 is rotated to the detection position, the baffle restricts the rotating member 143 from rotating further, thereby confirming that the rotation is in place. In addition, the baffle can also limit the rotation range of the rotating member 143, so that the rotating member 143 rotates along a predetermined path, preventing the rotating member 143 from rotating in the opposite direction and affecting other components in the sample chamber 110.

[0038] In one embodiment of this application, the fixing member 142 is further provided with a first fixing structure (not shown), and the rotating member 143 is provided with a second fixing structure (not shown). When the detection part 144 is in the clearance position, the first fixing structure and the second fixing structure cooperate to fix the detection part 144 in the clearance position. More specifically, the first fixing member 142 can be a threaded hole, and the second fixing structure can be a captive screw. By screwing the captive screw into the threaded hole, the detection part 144 can be fixed in the clearance position, preventing the detection part 144 from rotating.

[0039] like Figure 3 As shown in the view, when the scanning electron microscope 100 is placed at this view, since the detector 144 and the rotating member 143 have a certain mass, in another embodiment of this application, even without the first and second fixing structures, the detector 144 and the rotating member 143 can be relatively stably positioned in the clearance position under their own gravity, and the rotating member 143 and the detector 144 will not rotate arbitrarily.

[0040] Please refer to Figure 4 The fixing member 142 is provided with a first connecting structure 1424, and the rotating member 143 is provided with a second connecting structure 1431. The second connecting structure 1431 is rotatably connected to the first connecting structure 1424 so that the rotating member 143 can rotate relative to the fixing member 142.

[0041] In this application, the first connecting structure 1424 and the second connecting structure 1431 can facilitate the rotation of the rotating member 143 relative to the fixed member 142. In one embodiment of this application, the first connecting structure 1424 is a light hole and the second connecting structure 1431 is a rotating shaft.

[0042] Please refer to Figure 4 The fixing member 142 is also provided with a third connecting structure 1425, and the rotating member 143 is provided with a fourth connecting structure 1432. When the detection unit 144 rotates to the detection position, the fourth connecting structure 1432 connects with the third connecting structure 1425 to fix the detection unit 144 in the detection position.

[0043] When the detector 144 is in the detector position, the position of the detector can be further fixed by providing a third connecting structure 1425 on the fixing member 142 and a fourth connecting structure 1432 on the rotating member 143, preventing the detector from leaving the detector position due to external factors and affecting the imaging effect. In one embodiment of this application, the third connecting structure 1425 is a threaded hole, and the fourth connecting structure 1432 is a captive screw, which is inserted into the rotating member 143.

[0044] In other embodiments, the third connecting structure 1425 may also be a through hole, and the fourth connecting structure 1432 may be a pin.

[0045] Please refer to Figure 4-5 In some embodiments of this application, the rotation angle of the movable support 141 is 60°-180°. Specifically, it can be 60°, 90°, 110°, 130°, 150° or 180°, which can be set according to the actual use and is not specifically limited thereto.

[0046] In other embodiments, the third connecting structure 1425 can also be a through hole or a groove, and the fourth connecting structure 1432 can be a top bead. Specifically, the top bead can have an upper end and a lower end, and the top bead can penetrate the rotating member 143 in a vertical direction. The top bead and the rotating member 143 are connected by a spring, so that the top bead tends to protrude upward under the action of the spring. The upper end of the top bead protrudes from the upper surface of the rotating member 143, and the lower end of the top bead protrudes from the lower surface of the rotating member 143. When the detection part 144 is fixed in the detection position, the upper end protrudes from the upper surface of the rotating member 143 and is embedded in the third connecting structure 1425 provided in the fixing member 142, thereby defining the position of the rotating member 143. When it is necessary to rotate the detection part 144 to the clearance position, the lower end can be pulled down to retract the upper end from the upper surface of the rotating member 143. At this time, the rotating member 143 can be rotated until the detection part 144 rotates to the detection position.

[0047] In this embodiment, the first fixing structure can also be a through hole or a groove. After the detection part 144 rotates to the detection position, the lower end can be released, and the top ball tends to protrude upward again under the action of the spring. The upper end protrudes from the upper surface of the rotating part 143 and is embedded in the first fixing structure provided in the fixing part 142, thereby defining the position of the rotating part 143. This structure can effectively simplify the operation, and the position of the backscattered electron detection device 140 can be changed even without a screwdriver.

[0048] In this embodiment, the upper end can be spherical, and the first fixing structure and the third connecting structure 1425 can be hemispherical grooves or circular holes that match the size of the upper end.

[0049] It should be noted that although the rotation axis of the rotating component 143 in the attached figure is vertical, in other embodiments the rotation axis can also be designed to be horizontal. For example, after the rotating component 143 rotates 180° around the rotation axis (that is, the rotating component 143 flips 180°), the backscattered electron detection device 140 can face upward and be located next to the conical objective lens at the bottom of the lens barrel 120.

[0050] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A scanning electron microscope, characterized by, include: A sample chamber is provided with a sample stage, which is used to place samples. An electron beam is emitted from the sample chamber and spaced apart from the sample stage. A secondary electron detection device is installed in the sample chamber to detect secondary electrons generated by the sample; And a backscattered electron detection device is disposed in the sample chamber. The backscattered electron detection device includes a movable support and a detection part. The movable support is installed in the sample chamber. The detection part is connected to the movable support. The detection part includes a detection element for detecting backscattered electrons. At least a portion of the movable support is rotatable relative to the sample chamber, so that the probe can move between a clearance position and a probe position; When the detection unit is located at the detection position, the detection element is located on the line connecting the sample stage and the mirror barrel; when the detection unit is located at the avoidance position, the detection element is away from the line connecting the sample stage and the mirror barrel.

2. The scanning electron microscope of claim 1, wherein, The height of the movable support within the sample chamber is higher than that of the detector; The movable support includes a fixing component and a rotating component. The fixing component is fixed to the side wall of the sample chamber, the rotating component is rotatably connected to the fixing component, and the detection component is connected to the rotating component. The fixing component, the rotating component, and the detection component are arranged from top to bottom inside the sample chamber.

3. The scanning electron microscope of claim 2, wherein, The fixing component includes an installation end and a connecting end arranged opposite to each other. The installation end is connected to the side wall of the sample chamber, and the connecting end is rotatably connected to the rotating component. When the detection part is located at the detection position, the rotating component protrudes from the connecting end in a direction away from the installation end, and the detection part protrudes from the rotating component in a direction away from the connecting end.

4. The scanning electron microscope of claim 2, wherein, The fixing component is provided with a positioning structure. When the detection part is located at the detection position, the positioning structure is used to position the rotating component.

5. The scanning electron microscope of claim 4, wherein, The fixing member is further provided with a first fixing structure, and the rotating member is provided with a second fixing structure. When the detection part is located in the avoidance position, the first fixing structure and the second fixing structure cooperate to fix the detection part in the avoidance position.

6. The scanning electron microscope of claim 2, wherein, The fixing member is provided with a first connecting structure, and the rotating member is provided with a second connecting structure. The second connecting structure is rotatably connected to the first connecting structure so that the rotating member can rotate relative to the fixing member.

7. The scanning electron microscope of claim 6, wherein, The fixing member is further provided with a third connecting structure, and the rotating member is provided with a fourth connecting structure; when the detection part rotates to the detection position, the fourth connecting structure connects with the third connecting structure to fix the detection part at the detection position.

8. The scanning electron microscope as described in claim 6, wherein the fixing member is further provided with a third connecting structure, and the rotating member is provided with a fourth connecting structure, the third connecting structure being a through hole or a groove, the fourth connecting structure being a top bead, the top bead having an upper end and a lower end, and the top bead penetrating the rotating member in a vertical direction, the top bead being connected to the rotating member by a spring such that the top bead tends to protrude upward under the action of the spring, and the upper end protruding from the upper surface of the rotating member, and the lower end protruding from the lower surface of the rotating member.

9. The scanning electron microscope according to any one of claims 1-8, characterized in that, The rotation angle of the movable support is 60°-180°.

10. A backscattered electron detection device, characterized by include: Movable support, which is used to connect to the sample chamber; A detection unit is connected to the movable support unit. The detection unit includes a detector element for detecting backscattered electrons. At least a portion of the movable support unit is rotatable relative to the sample chamber, allowing the detection unit to move between a clearance position and a detection position. When the detection unit is located at the detection position, the detection element is located on the line connecting the sample stage and the mirror barrel; when the detection unit is located at the clearance position, the detection element is away from the line connecting the sample stage and the mirror barrel.

Images