One-stop four-dimensional transmission scanning focused ion beam double-beam electron microscope

Abstract

The invention relates to the technical field of in-situ detection of electron microscopes, in particular to a one-stop four-dimensional transmission scanning focused ion beam double-beam electron microscope, which comprises a vacuum cavity provided with a vacuum cavity cover; a sample table is arranged on the inner side of the vacuum cavity cover; the electron beam, the ion beam, the manipulator, the sample holder and the gas injection system are mounted on the vacuum cavity through the multifunctional in-situ sealing flange; the system further comprises a 4D STEM detector. According to the invention, electron beam observation, ion beam processing, four-dimensional scanning transmission electron microscope imaging information acquisition and in-situ electric, optical, thermal, force and other external field loading functions are integrated, and scanning electron microscope imaging, transmission electron microscope sample preparation and in-situ 4D STEM diffraction information acquisition under multi-field combined application can be carried out on a sample in one device. One-stop full-scale multi-field combined application detection is realized, the test result is prevented from being influenced by contact with air, water and other external environments in the sample transfer process, and meanwhile, the test efficiency is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of in-situ detection technology of electron microscopy, and in particular to a one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope. Background Technology

[0002] Traditional dual-beam electron microscopes (DEMs) are equipped with a scanning electron beam (SEM) and a focused ion beam (FIP). The SEM is incident on the sample surface, and by exciting secondary electrons and backscattering electrons, the microscopic morphology of the sample surface can be observed. The FIP combines imaging and micro / nano structure fabrication functions. However, with the development of the semiconductor integrated circuit and new energy battery industries, the demand for high-precision, multi-dimensional characterization of materials and devices is becoming increasingly strong. 4D STEM (four-dimensional transmission scanning electron microscopy) technology can collect information on different momentum electrons incident on the sample, enabling multi-dimensional characterization of the sample's composition, microstructure, internal defects, doping concentration, stress distribution, and other information. This can support the improvement of advanced process yields and contribute to the development of high-energy-density, long-cycle-life batteries.

[0003] Traditional 4D STEM is performed using a transmission electron microscope and has never been integrated into a dual-beam electron microscope. However, integrating 4D STEM functionality into a dual-beam electron microscope allows for in-situ multi-field combined application of electrical, optical, thermal, and mechanical fields to perform scanning electron microscopy imaging, transmission electron microscopy sample preparation, and in-situ 4D STEM diffraction information acquisition. This provides in-situ observation data across the entire scale from millimeters to micrometers to nanometers to atoms, enabling one-stop, multi-field combined application detection across all scales. Simultaneously, it avoids the influence of external environmental factors such as air and water during sample transfer, significantly improving testing efficiency. Currently, no such system or device exists. Summary of the Invention

[0004] The purpose of this invention is to provide a one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope.

[0005] The present invention achieves the above objectives through the following technical solution: a one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope, comprising: a vacuum chamber, the vacuum chamber being provided with a vacuum chamber cover; a sample stage being provided inside the vacuum chamber cover; an electron beam, an ion beam, a robotic arm, a sample holder and a gas injection system; a multifunctional in-situ sealing flange that can introduce an in-situ external field; and also includes a 4D STEM detector.

[0006] Electron beams are used for scanning electron microscopy imaging characterization.

[0007] The ion beam is mainly a liquid metal ion source of liquid Ga+ metal, used for sample observation and processing.

[0008] Robotic arms are used to extract and transfer samples.

[0009] Multifunctional in-situ sealing flanges can introduce external fields such as electricity, light, heat, and force through external flanges to implement in-situ external field loading.

[0010] The 4D STEM detector can be fixed at the bottom of the vacuum chamber or installed on the side wall of the vacuum chamber as a retractable device, used to acquire two-dimensional orthogonal electron microscopy imaging and two-dimensional reciprocal diffraction information of the sample.

[0011] The sample holder can be equipped with a large grid on which prepared samples to be observed by 4D STEM can be placed; the grid is fixed by screws and clamps.

[0012] The vacuum chamber provides the vacuum environment required for sample experiments.

[0013] The vacuum chamber cover is sealed to the opening of the vacuum chamber.

[0014] The sample stage is used to place samples to be observed or processed. It can be tilted, rotated, and moved up, down, left, right, forward, and backward. It is fixed on the vacuum chamber cover.

[0015] Gas injection system for deposition processing on sample surfaces.

[0016] This invention integrates functions such as scanning electron microscopy, scanning transmission electron microscopy, four-dimensional scanning transmission electron microscopy mapping reconstruction, focused ion beam observation and processing, and in-situ external field loading into a single device, enabling them to work collaboratively and significantly improving testing efficiency.

[0017] This device can obtain secondary electron images (surface morphology), two-dimensional atomically resolved lattice images, and two-dimensional reciprocal diffraction information of a sample in one stop, thereby obtaining the microscopic distribution of strain and electric field without opening the chamber to transfer the sample (which carries the potential risk of exposure to air and moisture).

[0018] The sample stage can be connected to an external flange to apply electric, thermal, laser, and stress fields to the sample under test in situ, thereby obtaining SEM, FIB processing, and 4D STEM inspection under in-situ applied external field conditions, meeting the requirements for in-situ testing of chip and battery materials and devices.

[0019] In addition to metal needles, the robotic arm can also be equipped with glass needles to transfer sensitive samples using electrostatic attraction without introducing ion beam irradiation damage (ion beam cutting and ion beam-assisted deposition welding).

[0020] This invention can operate in multiple modes depending on the actual sample conditions and testing situation, including: 1) directly performing 4D STEM testing under FIB processing and in-situ testing conditions; 2) using a robotic arm to sample for 4D STEM testing; 3) performing 4D STEM testing on multiple samples on a side-insertion sample stage, etc. Specifically:

[0021] (1) 4D-STEM mode under in-situ testing and FIB processing conditions: Under a working voltage of 30kV, it can generally penetrate samples with a thickness of less than 20nm. For samples with a thickness of less than 20nm, 4D STEM detection can be performed directly on the sample.

[0022] (2) 4D-STEM mode of robotic arm sampling: When the thickness of the sample is greater than 20nm, the scanning electron beam cannot penetrate the sample. Therefore, it is necessary to use a focused ion beam to cut the sample to make its thickness reach 50-100nm. Then, the robotic arm is used to break the sample to form a sufficiently thin fracture surface. The fracture surface is then subjected to 4D STEM detection.

[0023] (3) 4D-STEM mode of multiple samples in side-insertion sample stage: When multiple samples need to be detected, it can be achieved by side-insertion sample holder. The sample holder can be inserted into the cavity by side insertion. The samples prepared by the robot can be placed on this sample holder. After multiple sample preparations and multiple sample placements, the 4D STEM detector is used to collect 4D STEM information of each sample.

[0024] Compared with existing technologies, the advantages of this invention, a one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope, are:

[0025] 1. This invention can obtain secondary electronic images (surface morphology), two-dimensional positive space atomic resolution lattice images, and two-dimensional reciprocal space diffraction information of a sample in one stop, thereby obtaining the microscopic distribution of strain and electric field without opening the chamber to transfer the sample (which has the potential risk of exposure to air and moisture).

[0026] 2. This invention supports multiple operating modes, including direct 4D STEM inspection under FIB processing conditions, 4D STEM inspection using a robotic arm to sample samples, and 4D STEM inspection of multiple samples on a side-insertion sample stage.

[0027] 3. It also integrates a multi-functional in-situ external field loading setting, which can apply electric field, thermal field, laser field and stress field in situ to meet the needs of in-situ testing of chips, battery materials and devices;

[0028] 4. When transferring samples, the transmission electron microscope sample can be transferred by electrostatic attraction using a glass needle without introducing ion beam irradiation damage, ensuring that the sample is not affected by the sample preparation process. Attached Figure Description

[0029] Figure 1 This is one of the structural schematic diagrams of the present invention;

[0030] Figure 2This is one of the structural schematic diagrams of the present invention;

[0031] Figure 3 This is one of the detailed views of the sample holder;

[0032] Figure 4 This is a diagram showing the working state of Mode 1 of the present invention;

[0033] Figure 5 This is a diagram showing the working state of Mode 2 of the present invention;

[0034] Figure 6 This is a diagram of the working state of Mode 3 of the present invention;

[0035] Figure 7 This is the transmission diffraction pattern obtained in Example 1;

[0036] Figure 8 According to Figure 7 Topographic image reconstructed from diffraction pattern;

[0037] Figure 9 This is the transmission diffraction pattern obtained in Example 2;

[0038] Figure 10 According to Figure 9 Topographical image reconstructed from diffraction pattern. Detailed Implementation

[0039] like Figure 1 and Figure 2 The one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope shown is characterized by including: a vacuum chamber 9, used to provide the vacuum environment required for sample experiments;

[0040] The vacuum chamber 9 is equipped with a vacuum chamber cover 10; a sample stage 8 is located inside the vacuum chamber cover 10; the sample stage 8 is used to place samples to be observed or processed, and can rotate, move up and down, left and right, forward and backward.

[0041] Electron beam 1, ion beam 2, robotic arm 3, sample holder 4, and gas injection system 11 are mounted on vacuum chamber 9 via multifunctional in-situ sealing flange 5;

[0042] Electron beam 1 is used for scanning electron microscopy imaging characterization;

[0043] Ion beam 2 is a liquid metal ion source for liquid Ga+ metal, used for sample observation and processing;

[0044] The robotic arm 3 is used to extract and transfer samples; the robotic arm 3 is equipped with metal needles and glass needles.

[0045] Sample holder 4 is used to place prepared samples for 4D STEM observation; such as Figure 3The sample holder 4 is equipped with a carrier net 403, which is fixed by screws 401 and pressure plate 402.

[0046] The gas injection system 11 is used for deposition processing on the sample surface;

[0047] It also includes a 4D STEM detector, which is either a side-mounted 4D STEM detector 6 or a 4D STEM detector 7 fixed to the bottom of the vacuum chamber 9. The 4D STEM detector is used to acquire two-dimensional orthogonal electron microscopy imaging and two-dimensional reciprocal diffraction information of the sample.

[0048] The operation method of a one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope includes the following modes and corresponding steps:

[0049] Mode 1, such as Figure 4 4D-STEM mode under in-situ testing and FIB processing conditions: For samples with small thickness (less than 20 nm), the sample is placed on the sample stage 8, the sample stage 8 is moved so that the sample observation area is under the electron beam 1, and the scattered electron information is collected using a 4D STEM detector.

[0050] Mode 2, such as Figure 5 4D-STEM mode for robotic arm sampling: For samples with a large thickness (greater than 20nm), the sample is placed on the sample stage 8, and the selected area of ​​the sample is cut and processed using the focused ion beam 2 to make its thickness reach the range of 50-100nm. The sample is then broken by the robotic arm 3 to form a sufficiently thin fracture. The robotic arm 3 adsorbs this broken sample and moves it under the electron beam 1, where the scattered electron information is collected using a 4D STEM detector.

[0051] Mode 3, such as Figure 6 Multiple sample 4D-STEM mode with side-insertion sample stage: For scenarios that require the detection of multiple samples, the sample is placed on the sample stage 8, and the target area of ​​the sample is processed by the focused ion beam 2 and the robotic arm 3. Then, the robotic arm 3 adsorbs the prepared sample onto the carrier 403 on the side-insertion sample holder 4. The carrier 403 is fixed by screws 401 and pressure plate 402. The above sample preparation and placement process is completed for multiple target samples and areas one by one. After that, the 4D STEM detector is used to collect detection information of the target samples one by one.

[0052] Example 1

[0053] On a Thermo Fisher Helios G4 CX dual-beam focused ion microscope, a Felies camera from Amsterdam Scientific Instruments (ASI) is mounted at the vacuum pump evacuation port at the bottom center of the vacuum chamber. The camera probe is located at the evacuation port, but an evacuation channel is left open (i.e., the vacuum pumping is unaffected). When switching from normal FIB mode to 4D-STEM mode, the sample stage rotates 60 degrees, exposing the bottom camera and entering scanning transmission observation mode. In this mode, a robotic arm with an alloy needle is used to transfer a sheet-like two-dimensional MoS2 single-atom layer (10 nm x 10 nm) to the 4D-STEM working position. Figure 7 This is the transmission diffraction pattern obtained in Example 1. Figure 8 According to Figure 7 Topographical image reconstructed from diffraction pattern.

[0054] Example 2

[0055] Based on the DB550 focused ion beam dual-beam electron microscope from Guoyi Quantum, a Huangshan Timepix camera (SEM model) from Suzhou Suruit Technology Co., Ltd. was installed side-inserted into the vacuum cavity. The camera probe is retractable; in normal FIB operating mode, the probe is pulled out (located on the sidewall of the vacuum cavity, without interfering with FIB operation). When switching from normal FIB operating mode to 4D-STEM mode, the FIB sample stage rotates 70 degrees, and the Huangshan camera probe is inserted into the center of the vacuum cavity, entering scanning transmission observation mode. In this mode, the glass needle of the FIB's built-in robotic arm is used for electrostatic adsorption and transfer to move the MoS2 sheet-like structure doped in the battery material to the 4D-STEM working position. Figure 9 This is the transmission diffraction pattern obtained in Example 2. Figure 10 According to Figure 9 Topographical image reconstructed from diffraction pattern.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope, characterized in that, include: Vacuum chamber (9) is used to provide the vacuum environment required for sample experiments; The vacuum chamber (9) is equipped with a vacuum chamber cover (10); a sample stage (8) is provided inside the vacuum chamber cover (10); the sample stage (8) is used to place the sample to be observed or processed, and can rotate, move up and down, left and right, forward and backward. Electron beam (1), ion beam (2), robotic arm (3), sample holder (4) and gas injection system (11) are installed on vacuum chamber (9). Multifunctional in-situ sealing flange (5) is used to introduce electric, optical, thermal and mechanical external fields to implement in-situ external field loading. An electron beam (1) is generated for scanning electron microscopy imaging characterization; The ion beam (2) is a liquid metal ion source for liquid Ga+ metal, used for sample observation and processing; The robotic arm (3) is used to extract and transfer samples; The sample holder (4) is used to place the prepared samples to be observed; The gas injection system (11) is used for etching and deposition processing on the sample surface; It also includes a 4D STEM detector, which is either a side-mounted 4D STEM detector (6) or a 4D STEM detector (7) fixed to the bottom of the vacuum chamber (9). The 4D STEM detector is used to acquire two-dimensional positive space electron microscopy imaging and two-dimensional reciprocal space diffraction information of the sample.

2. The one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope according to claim 1, characterized in that, The sample holder (4) is provided with a carrier net (403), which is fixed by screws (401) and pressure plate (402).

3. The one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope according to claim 1, characterized in that... The robotic arm (3) is equipped with metal needles and glass needles.

4. The one-stop four-dimensional transmission scanning focused ion beam dual-beam electron microscope according to claim 1, characterized in that, The following working modes are included: 4D-STEM mode under in-situ testing and FIB processing conditions: Under a working voltage of 30kV, 4D STEM detection is performed directly on samples with a thickness of less than 20nm. 4D-STEM mode of robotic arm sampling: When the thickness of the sample itself is greater than 20nm, the sample is cut and processed by ion beam (2) to make its thickness reach 50-100nm range, and then the sample is broken by robotic arm (3) to form a sufficiently thin fracture surface in the sample, and then the fracture surface is detected by 4D STEM. 4D-STEM mode for multiple samples in side-insertion sample stage: When multiple samples need to be detected, it is achieved by using a side-insertion sample holder (4). The sample holder (4) is inserted into the cavity by side insertion. The samples prepared by the robot (3) are placed on the sample holder (4). After multiple sample preparations and multiple sample placements, the 4D STEM detector is used to collect 4D STEM information from each sample.

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