Charged particle beam device and control method thereof

Abstract

The present invention provides a charged particle beam device and a control method thereof. The charged particle beam device includes: a particle source for releasing a charged particle beam; a microscope column including: an objective lens for focusing the charged particle beam; an imaging system for photographing a sample to obtain height information and plane information of the sample surface; a motion stage for carrying and driving the sample to move; and a control unit for, in response to the motion stage driving the sample to move, compensating the focal length of the objective lens and / or controlling the distance between the sample and the microscope column based on the height information and plane information of the sample surface. The present application implements automatic focusing of a charged particle beam device and / or charged particle beam device and sample protection.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a charged particle beam device and a control method thereof. Background Art

[0002] When photographing a sample's surface topography using a charged particle beam device, the objective lens's focal length must be adjusted to ensure the charged particle beam emitted from the particle source converges on the sample surface, resulting in a clear image of the topography. However, if the sample surface is uneven, the lens must be constantly adjusted manually to obtain a clear image of the sample's topography while moving the sample to capture images of different locations on the surface. This is very inconvenient in practice.

[0003] In addition, when the sample surface has ups and downs, there is a risk that the sample surface may collide with the microscope column of the charged particle beam device when the sample is moved, thereby damaging the microscope column of the charged particle beam device or damaging the sample.

[0004] Therefore, how to achieve automatic focusing of a charged particle beam device and / or protection of the charged particle beam device and samples is a technical problem that needs to be urgently solved in this field. Summary of the Invention

[0005] In order to overcome the defects of the above-mentioned related technologies, the present invention provides a charged particle beam device and a control method thereof, which realize automatic focusing of the charged particle beam device and / or protection of the charged particle beam device and samples.

[0006] According to one aspect of the present invention, there is provided a charged particle beam apparatus comprising:

[0007] a particle source for releasing a charged particle beam;

[0008] Microscope column, including:

[0009] an objective lens, for focusing the charged particle beam;

[0010] An imaging system, used to photograph a sample to obtain height information and plane information of the sample surface;

[0011] A motion platform, used for carrying and driving the sample to move;

[0012] A control unit is configured to move the sample in response to the motion stage, so as to compensate the focal length of the objective lens and / or control the distance between the sample and the microscope column according to the height information and plane information of the sample surface.

[0013] In some embodiments of the present application, a three-dimensional modeling unit is further included, and the motion stage can drive the sample to rotate so as to capture the height information of the sample at different rotation angles through the imaging system. The three-dimensional modeling unit establishes a three-dimensional model of the sample based on the plane information and the height information at different rotation angles, and the control unit compensates the focal length and / or controls the distance according to the three-dimensional model to achieve collision avoidance.

[0014] In some embodiments of the present application, the microscope column includes a component located between the objective lens and the sample, and the control unit controls the distance between the sample and the component according to the height information and the plane information in response to using the motion stage to move the sample to achieve collision avoidance.

[0015] In some embodiments of the present application, the component includes one or more of a deflector, a deceleration electrode, a signal electron attracting electrode, a focus compensation electrode, and an optical reflector.

[0016] In some embodiments of the present application, the control unit obtains coordinate information of the lowest position of the component and controls the distance according to the coordinate information, height information, and plane information.

[0017] In some embodiments of the present application, the number of the microscope columns is at least two, and the control unit obtains coordinate information of the lowest positions of at least two of the microscope columns, and controls the distance according to the coordinate information, height information, and plane information.

[0018] In some embodiments of the present application, the microscope column further comprises a focal length compensation electrode, which is disposed between the objective lens and the sample, and the control unit controls the operating parameters of the objective lens or the focal length compensation electrode to compensate for the focal length of the objective lens.

[0019] In some embodiments of the present application, the imaging system includes:

[0020] a first imaging unit, configured to photograph the side of the sample to obtain height information of the sample surface;

[0021] a second imaging unit, configured to photograph the surface of the sample to obtain plane information of the sample surface; and

[0022] A vacuum chamber, wherein the first imaging unit is mounted on a side wall of the vacuum chamber, and the second imaging unit is mounted on a top wall of the vacuum chamber;

[0023] Wherein, the motion platform is a five-axis motion platform; the control unit controls the motion platform to stop according to the height information and the plane information.

[0024] According to another aspect of the present application, a control method for a charged particle beam device is provided, which is applied to the charged particle beam device as described above, comprising:

[0025] Adjusting the position of the sample so that the imaging system can photograph the sample to obtain height information and plane information of the sample surface;

[0026] The control unit compensates the focal length of the objective lens and / or controls the distance between the sample and the microscope column according to the height information and the plane information of the sample surface.

[0027] In some embodiments of the present application, the imaging system includes a first imaging unit and a second imaging unit, wherein the first imaging unit is used to photograph the side of the sample to obtain height information of the sample surface, and the second imaging unit is used to photograph the surface of the sample to obtain plane information of the sample surface;

[0028] The step of adjusting the position of the sample so that the imaging system can photograph the sample to obtain height information and plane information of the sample surface includes:

[0029] Controlling the motion stage to adjust the position of the sample so that the sample is located within the imaging area of ​​the first imaging unit, and controlling the motion stage and the sample to rotate at least 180 degrees so that the first imaging unit can obtain height information of the sample surface at different rotation angles;

[0030] controlling the motion stage to adjust the position of the sample so that the sample is located within the imaging area of ​​the second imaging unit, so that the second imaging unit can obtain planar information of the sample surface;

[0031] The control unit compensates the focal length of the objective lens and / or controls the distance between the sample and the microscope column according to the height information and the plane information of the sample surface, including:

[0032] Establishing a three-dimensional model of the sample according to the plane information and the height information at different rotation angles;

[0033] The control unit compensates the focal length and / or controls the distance according to the three-dimensional model to achieve collision avoidance.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] The charged particle beam device is provided with an imaging system and a control unit, so that the imaging system photographs the sample to obtain height information and plane information of the sample surface. The control unit drives the sample to move in response to the motion stage, so as to compensate the focal length of the objective lens and / or control the distance between the sample and the microscope column according to the height information and plane information of the sample surface. Thus, the charged particle beam device can be automatically focused on the sample surface by compensating the focal length without manual adjustment, and a part of the time for collecting images and evaluating image clarity can be saved. The distance adjustment can avoid collision between the charged particle beam device and the sample, thereby protecting the charged particle beam device and the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other features and advantages of the present invention will become more apparent by describing in detail example embodiments thereof with reference to the accompanying drawings.

[0037] Figure 1 A schematic diagram of a charged particle beam device according to a first embodiment of the present invention is shown.

[0038] Figure 2 A side view of a sample according to an embodiment of the present invention is shown.

[0039] Figure 3 A top view of a sample according to an embodiment of the present invention is shown.

[0040] Figure 4 FIG. 1 is a schematic diagram showing a charged particle beam device according to a second embodiment of the present invention.

[0041] Figure 5 FIG. 1 is a schematic diagram showing a charged particle beam device according to a third embodiment of the present invention.

[0042] Figure 6 A schematic diagram of a charged particle beam device according to a fourth embodiment of the present invention is shown.

[0043] Figure 7 A schematic diagram of a charged particle beam device according to a fifth embodiment of the present invention is shown.

[0044] Figure 8 FIG. 1 is a schematic diagram showing a charged particle beam device according to a sixth embodiment of the present invention.

[0045] Figure 9 FIG. 1 is a schematic diagram showing a charged particle beam device according to a seventh embodiment of the present invention.

[0046] Figure 10 A schematic diagram of a charged particle beam device according to an eighth embodiment of the present invention is shown.

[0047] Figure 11FIG. 1 is a schematic diagram showing a charged particle beam device according to a ninth embodiment of the present invention.

[0048] Figure 12 A flow chart of a method for controlling a charged particle beam device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention will be comprehensive and complete, and the concept of the example embodiments will be fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, materials, devices, etc. may be adopted. In other cases, well-known technical solutions are not shown or described in detail to avoid blurring various aspects of the present disclosure. The same reference numerals in the figures represent the same or similar structures, and their detailed descriptions will be omitted.

[0050] The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including," "having," and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0051] The present invention provides a charged particle beam device and a control method thereof, which realize automatic focusing of the charged particle beam device and / or protection of the charged particle beam device and a sample.

[0052] See first Figure 1 , Figure 1 FIG2 is a schematic diagram of a charged particle beam apparatus according to a first embodiment of the present invention. The charged particle beam apparatus 100A includes a particle source 110 , a microscope column 120 , an imaging system 130 , a motion stage 140 , and a control unit 150 .

[0053] The particle source 110 is used to release a charged particle beam 111. In one embodiment, the particle source may be an electron source or an ion source.

[0054] The microscope column 120 includes an objective lens 121. The objective lens 121 is used to focus the charged particle beam 111. In various embodiments of the present application, the microscope column 120 can be a microscope column of a scanning electron microscope (SEM) or a microscope column of a focused ion beam microscope (FIB), but the present application is not limited to this. In one embodiment, the charged particle beam device includes a scanning electron microscope; in one embodiment, the charged particle beam device includes a focused ion beam microscope; in one embodiment, the charged particle beam device includes a dual-beam device, that is, a FIB-SEM device. The microscope column 120 can include one or more lenses. When the microscope column 120 includes only one lens, the lens is the objective lens 121 of the microscope column 120. When the microscope column 120 includes multiple lenses, the lens closest to the sample is the objective lens 121 of the microscope column 120. Furthermore, when the microscope column 120 includes multiple lenses, the multiple lenses are arranged along the release direction of the charged particle beam 111 to focus the charged particle beam 111. The lenses of the microscope column 120 can be magnetic lenses, electrostatic lenses, etc., and the present application is not limited thereto.

[0055] The microscope column 120 may further include a deflector. In some embodiments, the deflector may be used to deflect the charged particle beam 111 to scan the sample 10 to generate an excitation signal (the excitation signal may include signal electrons and photons), thereby collecting the excitation signal through a detector and imaging. In other embodiments, the deflector may also deflect the charged particle beam 111 so that it deviates from the optical axis to achieve beam blanking. The deflector may be located on the side of the objective lens 121 away from the sample 10 to form a pre-lens deflector; located in the objective lens 121 to form an in-lens deflector; located between the objective lens 121 and the sample 10 to form a post-lens deflector. The different arrangement positions of the deflector are all within the scope of protection of this application and will not be described in detail herein.

[0056] The imaging system 130 is used to photograph the sample 10 to obtain height information and plane information of the surface of the sample 10. Specifically, the imaging system 130 may include one or more imaging units to photograph the sample 10 at different angles. The imaging unit may be a semiconductor photosensitive element, but the present application is not limited thereto. Specifically, see Figure 2 and Figure 3The height information of the surface of sample 10 may include the heights of protrusions (e.g., numbers 11, 12, and 13) on the surface of sample 10; the plane information of the surface of sample 10 may include the positions of the protrusions (e.g., numbers 11, 12, and 13) on the surface of sample 10. The positions of the protrusions (e.g., numbers 11, 12, and 13) on the surface of sample 10 may be represented, for example, by the horizontal and vertical coordinates of the protrusions in a preset plane coordinate system. This application is not limited to this, and other position representation methods are also within the scope of protection of this application.

[0057] The motion stage 140 is used to carry and drive the sample 10. The motion stage 140 can be a multi-axis motion stage to control the lifting, translation, and rotation of the sample 10. It can be configured based on specific movement requirements. In one embodiment, the motion stage is a five-axis motion stage, and the five axes include an X-axis translation axis, a Y-axis translation axis, a Z-axis elevation axis, a Z-axis rotation axis, and a tilt axis. The X and Y directions are two mutually perpendicular directions in a plane, and the Z direction is a height direction and is perpendicular to the X and Y directions, respectively. Details are omitted here.

[0058] The control unit moves the sample 10 in response to the motion stage 140 to compensate the focal length of the objective lens 121 and / or control the distance between the sample 10 and the microscope column 120 according to the height information and plane information of the surface of the sample 10 .

[0059] In the prior art, if there are uneven areas on the sample, then after the relative position between the sample and the charged particle beam changes (for example, by controlling the workbench to move the sample via a control unit), causing the charged particle beam device to switch from a first observation area on the sample to a second observation area, it is usually necessary to refocus the charged particle beam device. The focusing process involves changing the operating parameters of the objective lens to change the focal length of the objective lens, and capturing a frame of image at different focal lengths in the second observation area to form a total of multiple frames of image. The clarity of the multiple frames of image is evaluated to select the operating parameters and focal length of the objective lens that correspond to the best clarity, completing the focusing.

[0060] In an embodiment of the present invention, the focal length of the objective lens before the sample moves can be obtained by a focusing process. As described above, multiple frames of images are collected and the clarity of the multiple frames of images is evaluated, and the working parameters and focal length of the objective lens corresponding to the image with the best clarity are selected. As for the focal length of the objective lens corresponding to other positions (the real-time position when the sample moves or the position after the sample movement stops), there is no need to collect images with different focal lengths and evaluate the clarity of the image to obtain the focal length of the objective lens corresponding to other positions. Instead, the control unit 150 compensates the focal length of the objective lens 121 according to the height information and plane information of the sample surface to obtain the focal length of the objective lens corresponding to other positions. It can be seen that the time for collecting images and performing image clarity evaluation can be saved, and the efficiency of obtaining the focal length of the charged particle beam can be improved. Among them, the clarity corresponding to the multiple frames of images can be obtained based on the image clarity evaluation algorithm or manual evaluation, which will not be repeated here.

[0061] In one embodiment, the control unit is responsive to the motion stage driving the sample to move so as to compensate the focal length of the objective lens according to the height information, the plane information, the focal length before the movement, and the height-focal length relationship table. The height-focal length relationship table is a relationship table of sample height change values ​​and focal length change values ​​acquired in advance. For example, the height change value of the sample surface before and after the motion stage is obtained, the corresponding focal length change value is obtained according to the height-focal length relationship table, and the focal length of the objective lens is compensated according to the focal length before the movement and the focal length change value, so that the objective lens is compensated from the first focal length before the sample movement to the second focal length after the sample movement.

[0062] In one embodiment, when the moving stage drives the sample to move, the height information and plane information of the sample surface at each moment are obtained in real time, and then the corresponding compensated focal length is obtained. Real-time imaging can be performed based on the compensated focal length, that is, continuous imaging of the sample while it moves is achieved. In another embodiment, after the moving stage drives the sample to move, the height information and plane information of the sample surface after the movement are obtained, and then the corresponding compensated focal length is obtained, that is, the compensated focal length after the moving stage moves to a position is obtained, and an image of the position is obtained based on the compensated focal length, thereby achieving imaging when the sample stage moves to any position.

[0063] Furthermore, when the distance between the sample 10 and the microscope column 120 is small and a collision is about to occur, the control unit 150 can control the motion stage 140 to stop moving so that the sample 10 maintains a certain distance from the end of the microscope column 120 to avoid a collision between the sample 10 and the microscope column 120.

[0064] Therefore, the charged particle beam device of the present application is provided with an imaging system and a control unit, so that the imaging system photographs the sample to obtain the height information and plane information of the sample surface. The control unit drives the sample to move in response to the motion stage to compensate the focal length of the objective lens and / or control the distance between the sample and the microscope column according to the height information and plane information of the sample surface. Thus, the charged particle beam device can be automatically focused on the sample surface by compensating the focal length without manual adjustment, and can save some time for collecting images and evaluating image clarity. The distance adjustment can avoid collision between the charged particle beam device and the sample, thereby protecting the charged particle beam device and the sample.

[0065] See below Figure 4 , Figure 4 FIG2 is a schematic diagram of a charged particle beam apparatus according to a second embodiment of the present invention. The charged particle beam apparatus 100B includes a particle source 110 , a microscope column 120 , an imaging system 130 , a motion stage 140 , a control unit 150 , and a 3D modeling unit 160 .

[0066] In this embodiment, the motion stage 140 can drive the sample 10 to rotate so as to capture the height information of the sample 10 at different rotation angles through the imaging system 130. For example, the motion stage 140 can drive the sample 10 to rotate around the axis of the sample, i.e., around the Z axis, in the horizontal plane, so that the imaging system 130 can capture the side view of the sample 10 at different rotation angles to obtain the height information of the sample 10 at different rotation angles. The three-dimensional modeling unit 160 can establish a three-dimensional model of the sample based on the plane information and the height information at different rotation angles. Specifically, since the imaging system 130 can capture the side view of the sample 10 at different rotation angles to obtain the height information of the sample 10 at different rotation angles, the corresponding relationship between the protrusions on the surface of the sample 10 and the horizontal information can be determined in combination with the horizontal information of the sample 10 obtained by the imaging system 130. For example, in combination Figure 2 and Figure 3 The horizontal position and height information of protrusions 11, 12, and 13 on the surface of sample 10 can be determined based on the top view of sample 10 and the side view of sample 10 at different rotation angles, thereby obtaining a three-dimensional model of sample 10. The control unit 150 can compensate the focal length based on the three-dimensional model. The control unit 150 can also control the distance based on the three-dimensional model to achieve collision avoidance. The focal length compensation function and the collision avoidance function can be implemented separately or simultaneously.

[0067] In some embodiments of the present application, the microscope column 120 includes an objective lens 121. The control unit 150, in response to the motion stage 140 driving the sample 10 to move, controls the distance between the sample 10 and the objective lens 121 based on the height information and the plane information to achieve collision avoidance. The control unit 150 may also obtain coordinate information of the lowest position of the objective lens and control the distance based on the coordinate information, the height information, and the plane information.

[0068] In some embodiments of the present application, the microscope column 120 may further include a component located between the objective lens 121 and the sample 10. Thus, the control unit 150, in response to the motion stage 140 driving the sample 10 to move, controls the distance between the sample 10 and the component based on the height information and plane information to achieve collision avoidance. The control unit 150 may also obtain coordinate information of the lowest position of the component and control the distance based on the coordinate information, height information, and plane information.

[0069] The following are combined Figures 5 to 9 , various different embodiments of the microscope column 120 including components located between the objective lens 121 and the sample 10 are described.

[0070] See below Figure 5 , Figure 5 A schematic diagram of a charged particle beam device according to a third embodiment of the present invention is shown. The charged particle beam device 100C includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, a control unit 150, and a deflector 122. In one embodiment, the deflector 122 can be used to deflect the charged particle beam 111 to scan the sample 10 to generate an excitation signal. In this embodiment, the deflector 122 is located between the objective lens 121 and the sample 10, and the control unit 150 drives the sample 10 to move in response to the motion stage 140 to control the distance between the sample 10 and the deflector 122 according to the height information and the plane information to achieve collision avoidance. Specifically, the control unit 150 can also obtain the coordinate information of the lowest position of the deflector 122, and control the distance between the sample 10 and the deflector 122 according to the coordinate information of the lowest position of the deflector 122, the height information of the sample 10, and the plane information.

[0071] See below Figure 6 , Figure 6A schematic diagram of a charged particle beam apparatus according to a fourth embodiment of the present invention is shown. The charged particle beam apparatus 100D includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, a control unit 150, and a deceleration electrode 124. The deceleration electrode 124 is grounded via a power supply, and the sample 10 is grounded. A deceleration electric field for the charged particle beam 111 is formed between the deceleration electrode 124 and the sample 10. The charged particle beam 111 is decelerated as it passes through this electric field, reducing damage to the sample caused by the charged particle beam and improving the low-voltage resolution of the topographic image of the surface of the sample 10. In one embodiment, the particle source includes an electron source, the charged particle beam includes an electron beam, the power supply applies a negative voltage to the deceleration electrode, the sample is grounded, and the negatively charged electron beam is decelerated between the deceleration electrode and the sample. In another embodiment, the particle source includes an ion source, the charged particle beam includes an ion beam, the power supply applies a positive voltage to the deceleration electrode, the sample is grounded, and the positively charged ion beam is decelerated between the deceleration electrode and the sample. In this embodiment, the deceleration electrode 124 is located between the objective lens 121 and the sample 10. The control unit 150, in response to the motion stage 140 driving the sample 10 to move, controls the distance between the sample 10 and the deceleration electrode 124 based on the height information and the plane information to achieve collision avoidance. Specifically, the control unit 150 may also obtain coordinate information of the lowest position of the deceleration electrode 124 and control the distance between the sample 10 and the deceleration electrode 124 based on the coordinate information of the lowest position of the deceleration electrode 124, the height information of the sample 10, and the plane information.

[0072] See below Figure 7 , Figure 7 A schematic diagram of a charged particle beam device according to a fifth embodiment of the present invention is shown. The charged particle beam device 100E includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, a control unit 150, and a focus compensation electrode 125. In this embodiment, the focus compensation electrode 125 is located between the objective lens 121 and the sample 10. The control unit 150 drives the sample 10 in motion in response to the motion stage 140 to control the distance between the sample 10 and the focus compensation electrode 125 based on the height information and plane information to achieve collision avoidance. Specifically, the control unit 150 can also obtain the coordinate information of the lowest position of the focus compensation electrode 125 and control the distance between the sample 10 and the focus compensation electrode 125 based on the coordinate information of the lowest position of the focus compensation electrode 125, the height information of the sample 10, and the plane information. Furthermore, the control unit 150 can also control the operating parameters of the objective lens 121 or the focus compensation electrode 125 to compensate for the focal length of the objective lens 121, thereby achieving automatic focusing.

[0073] See below Figure 8 , Figure 8A schematic diagram of a charged particle beam device according to a sixth embodiment of the present invention is shown. The charged particle beam device 100F includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, a control unit 150, and a signal electron attracting electrode 126. The signal electron attracting electrode 126 is used to attract signal electrons 112. The signal electrons 112 are generated by the charged particle beam 111 acting on the sample. The signal electrons 112 are detected by the electron detector 170 to obtain a morphological image of the surface of the sample 10. Secondary electrons and backscattered electrons are both signal electrons 112. In one embodiment, the signal electron attracting electrode 126 is used to attract secondary electrons and deflect them to the electron detector 170. In another embodiment, the signal electron attracting electrode 126 is used to attract backscattered electrons and convert them into secondary electrons, and then deflect the converted secondary electrons to the electron detector 170. In this embodiment, the signal electron attracting electrode 126 is located between the objective lens 121 and the sample 10. The control unit 150, in response to the motion stage 140 driving the sample 10 to move, controls the distance between the sample 10 and the signal electron attracting electrode 126 based on the height information and the plane information to achieve collision avoidance. Specifically, the control unit 150 can also obtain the coordinate information of the lowest position of the signal electron attracting electrode 126, and control the distance between the sample 10 and the signal electron attracting electrode 126 based on the coordinate information of the lowest position of the signal electron attracting electrode 126, the height information of the sample 10, and the plane information.

[0074] See below Figure 9 , Figure 9 Shown is a schematic diagram of a charged particle beam device according to a seventh embodiment of the present invention. Charged particle beam device 100G includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, a control unit 150 and an optical reflector 127. The optical reflector 127 reflects the photons 113 generated from the surface of the sample 10 to a photon detector 180 to obtain a topographic image of the surface of the sample 10. In one embodiment, the charged particle beam acts on the sample to generate cathode fluorescence (CL), and the optical reflector 127 is used to reflect the cathode fluorescence to the photon detector 180. In this embodiment, the optical reflector 127 is located between the objective lens 121 and the sample 10, and the control unit 150 drives the sample 10 to move in response to the motion stage 140, so as to control the distance between the sample 10 and the optical reflector 127 according to the height information and the plane information to achieve collision avoidance. Specifically, the control unit 150 can also obtain the coordinate information of the lowest position of the optical reflector 127, and control the distance between the sample 10 and the optical reflector 127 according to the coordinate information of the lowest position of the optical reflector 127, the height information and plane information of the sample 10.

[0075] See below Figure 10 , Figure 10 A schematic diagram of a charged particle beam device according to an eighth embodiment of the present invention is shown. The charged particle beam device 100H includes two particle sources 110A and 110B, two microscope columns 120A and 120B, an imaging system 130, a motion stage 140, and a control unit 150. In this embodiment, the particle source 110A is focused onto the surface of the sample 10 via the microscope column 120A, and the particle source 110B is focused onto the surface of the sample 10 via the microscope column 120B. The control unit 150 can obtain the coordinate information of the lowest position of the two microscope columns 120A and 120B, and control the shortest distance between the sample 10 and the microscope columns 120A and 120B based on the coordinate information of the lowest position of the microscope columns 120A and 120B, the height information of the surface of the sample 10, and the plane information. This embodiment schematically shows two microscope columns 120A and 120B, but the present application is not limited to this. The use of more than two microscope columns is also within the scope of protection of the present application.

[0076] See below Figure 11 , Figure 11 A schematic diagram of a charged particle beam device according to a ninth embodiment of the present invention is shown. The charged particle beam device 100I includes a particle source 110, a microscope column 120, an imaging system 130, a motion stage 140, and a control unit 150. The imaging system 130 may include a first imaging unit 131, a second imaging unit 132, and a vacuum chamber 190. The first imaging unit 131 is used to image the side of the sample 10 to obtain height information of the surface of the sample 10. The second imaging unit 132 is used to image the surface of the sample 10 to obtain plane information of the surface of the sample 10. The first imaging unit 131 can be mounted on the side wall of the vacuum chamber 190, and the second imaging unit 132 can be mounted on the top wall of the vacuum chamber 190. The first imaging unit 131 and the second imaging unit 132 can be located inside or outside the vacuum chamber 190, but this application is not limited to this. In this embodiment, the motion stage 140 can be a five-axis motion stage. The five-axis motion stage can move the sample 10 up and down, translate, rotate about its central axis, and rotate (i.e., tilt) in a horizontal direction along its surface. Thus, the control unit 150 can control the motion stage 140 to stop based on the height information and plane information. This stops the sample 10 when the distance between the sample 10 and the microscope column 120 falls below a set threshold, maintaining a certain distance between the sample 10 and the microscope column 120 to prevent collision between the sample 10 and the microscope column 120.

[0077] In one embodiment, the second imaging unit 132 captures a frame of image of the surface of the sample 10 to obtain planar information of the surface of the sample 10; in one embodiment, the second imaging unit 132 captures multiple frames of image of the surface of the sample 10 in the same field of view, selects one frame of image from the multiple frames of image according to preset conditions (such as a clarity threshold), and obtains planar information of the surface of the sample 10 based on the one frame of image; in one embodiment, the second imaging unit 132 captures multiple frames of image of the surface of the sample 10 in the same field of view, and takes the grayscale average of the multiple frames of image to obtain an averaged image, and obtains planar information of the surface of the sample 10 based on the image; in one embodiment, when the image of the sample 10 is captured by the second imaging unit 132 to obtain planar information of the surface of the sample 10, there is no need to rotate the sample 10.

[0078] Figure 1 、 Figures 4 to 11 The present invention is merely schematically illustrated in multiple embodiments. Each embodiment can be implemented independently or in combination. For example, the three-dimensional modeling unit can be implemented in Figure 5-11 In the embodiment, Figures 4 to 10 The number of microscope columns in the apparatus can be greater than two, and the present application is not limited thereto.

[0079] The present application also provides a control method for a charged particle beam device, which is applied to the charged particle beam device as described above. Figure 12 The control methods include:

[0080] Step S110: adjusting the position of the sample so that the imaging system can photograph the sample to obtain height information and plane information of the sample surface.

[0081] Step S120: the control unit compensates the focal length of the objective lens and / or controls the distance between the sample and the microscope column according to the height information and the plane information of the sample surface.

[0082] Specifically, when obtaining height information and plane information of the sample surface, the control method adjusts the position of the sample so that the sample is located within the imaging area of ​​the imaging system, so that the imaging system can capture the sample and, based on the captured image, obtain the height information and plane information of the sample surface. When observing the sample surface or obtaining a topographic image of the sample surface using a microscope column, the control unit compensates the focal length of the objective lens and / or controls the distance between the sample and the microscope column based on the height information and plane information of the sample surface. At the same time, by controlling the distance between the sample and the microscope column, collision between the sample and the microscope column is avoided.

[0083] In some specific embodiments, the imaging system may include a first imaging unit and a second imaging unit. The first imaging unit may be used to photograph the side of the sample to obtain height information of the sample surface. The second imaging unit may be used to photograph the surface of the sample to obtain plane information of the sample surface. Thus, when obtaining the height information and plane information of the sample surface, the control method may control the motion stage to adjust the position of the sample so that the sample is located within the imaging area of ​​the first imaging unit, and control the motion stage and the sample to rotate at least 180 degrees (for example, 360 degrees) for the first imaging unit to obtain the height information of the sample surface at different rotation angles. The control method may also control the motion stage to adjust the position of the sample so that the sample is located within the imaging area of ​​the second imaging unit, and for the second imaging unit to obtain the plane information of the sample surface. The height information and plane information of the sample surface at different rotation angles can be acquired in sequence. In some variations, the sample can be first placed within the imaging area of ​​the second imaging unit so that the second imaging unit can obtain planar information of the sample surface, and then the sample can be placed within the imaging area of ​​the first imaging unit, and the motion stage and the sample can be controlled to rotate at least 180 degrees so that the first imaging unit can obtain height information of the sample surface at different rotation angles.

[0084] In some specific embodiments, step S120 can be implemented by the following steps: establishing a three-dimensional model of the sample based on the plane information and the height information at different rotation angles; the control unit compensates the focal length and / or controls the distance according to the three-dimensional model to achieve collision avoidance. In this embodiment, a three-dimensional model of the sample can be established based on the plane information and the height information at different rotation angles. Specifically, since the first imaging unit of the imaging system can capture the side view of the sample at different rotation angles to obtain the height information of the sample at different rotation angles, the horizontal information of the sample 10 obtained by the second imaging unit can be combined to determine the correspondence between the protrusions on the sample surface and the horizontal information. For example, combined with Figure 2 and Figure 3 The horizontal positions of protrusions 11, 12, and 13 on the surface of sample 10 can be determined based on the side view and top view of sample 10 at different rotation angles, thereby obtaining a three-dimensional model of sample 10. Thus, step S120 can compensate for the focal length based on the three-dimensional model. Step S120 can also control the distance based on the three-dimensional model to achieve collision avoidance. The focal length compensation function and the collision avoidance function can be implemented separately or simultaneously.

[0085] Although relative terms such as "upper" and "lower" are used in this specification to describe the relationship of one component of the illustrations to another component, these terms are used in this specification for convenience only, such as based on the orientation of the examples shown in the drawings. It is understood that if the device in the illustrations is turned upside down, the component described as "upper" will become the component "lower". Other relative terms such as "higher", "lower", "top", "bottom", "left", and "right" have similar meanings. When a structure is "on" another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0086] Throughout this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," and "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. Throughout this specification, illustrative uses of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0087] The above description further details the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be construed as being limited to these descriptions. Those skilled in the art may make several simple deductions or substitutions without departing from the scope of the present invention, all of which should be considered to fall within the scope of protection of the present invention.

Claims

1. A charged particle beam device, characterized in that include: a particle source for releasing a charged particle beam; a microscope column comprising an objective lens and a component located between the objective lens and the sample, wherein the objective lens is used to focus the charged particle beam; An imaging system, used to photograph a sample to obtain height information and plane information of the sample surface; A motion platform, used for carrying and driving the sample to move; A control unit, in response to the motion stage driving the sample to move, compensates the focal length of the objective lens and controls the distance between the sample and the component to achieve collision avoidance according to the height information and plane information of the sample surface; or controls the distance between the sample and the component to achieve collision avoidance according to the height information and plane information of the sample surface.

2. The charged particle beam device according to claim 1, wherein It also includes a three-dimensional modeling unit, and the motion stage can drive the sample to rotate so that the height information of the sample at different rotation angles can be captured by the imaging system. The three-dimensional modeling unit establishes a three-dimensional model of the sample based on the plane information and the height information at different rotation angles. The control unit compensates the focal length and controls the distance according to the three-dimensional model to achieve collision avoidance; or, the control unit controls the distance according to the three-dimensional model to achieve collision avoidance.

3. The charged particle beam device according to claim 1, wherein The components include one or more of a deflector, a deceleration electrode, a signal electron attracting electrode, a focus compensation electrode, and an optical mirror.

4. The charged particle beam device according to claim 1, wherein The control unit obtains coordinate information of the lowest position of the component and controls the distance according to the coordinate information, height information, and plane information.

5. The charged particle beam device according to claim 1, wherein The number of the microscope columns is at least two, and the control unit obtains coordinate information of the lowest positions of at least two of the microscope columns, and controls the distance according to the coordinate information, height information, and plane information.

6. The charged particle beam device according to claim 1, wherein The microscope column further includes a focus compensation electrode, which is arranged between the objective lens and the sample. The control unit controls the working parameters of the objective lens or the focus compensation electrode to compensate for the focal length of the objective lens.

7. The charged particle beam device according to claim 1, wherein The imaging system comprises: a first imaging unit, configured to photograph the side of the sample to obtain height information of the sample surface; a second imaging unit, configured to photograph the surface of the sample to obtain plane information of the sample surface; and A vacuum chamber, wherein the first imaging unit is mounted on a side wall of the vacuum chamber, and the second imaging unit is mounted on a top wall of the vacuum chamber; Wherein, the motion platform is a five-axis motion platform; the control unit controls the motion platform to stop according to the height information and the plane information.

8. The charged particle beam device according to claim 1, wherein The control unit drives the sample to move in response to the motion stage, so as to compensate the focal length of the objective lens according to the height information, the plane information, the focal length before the movement, and the height-focal length relationship table.

9. A method for controlling a charged particle beam device, applied to the charged particle beam device according to any one of claims 1 to 8, characterized in that: include: Adjusting the position of the sample so that the imaging system can photograph the sample to obtain height information and plane information of the sample surface; The control unit compensates the focal length of the objective lens and / or controls the distance between the sample and the microscope column according to the height information and the plane information of the sample surface.

Images