CN114429894B - Scanning imaging fixing device and method using E-T secondary electron detector - Google Patents

Abstract

The invention discloses a scanning imaging fixing device and a method thereof by using an E-T secondary electron detector, wherein the device comprises a first component, a second component, screws and a copper mesh sample, wherein a row of locking holes and a row of grooves are arranged on the second component; the first assembly is provided with sample placement grooves, wherein copper mesh samples are placed on each sample placement groove, and screws penetrate through corresponding locking holes to fix the second assembly on the top of the first assembly. According to the method, a copper mesh transmission sample is placed in a groove-type sample stage, and a relative closed space is formed between the groove-type design and the bottom of the objective pole shoe to inhibit an E-T type secondary electron detector from obtaining surface information from the upper surface of the sample, so that the aim of scanning transmission imaging is fulfilled. The method has the advantages of simple process, good imaging effect and strong repeatability, and is suitable for various scanning electron microscopes.

Description

Obtaining scanning imaging fixture and method using E-T type secondary electron detector

Technical field

The invention relates to the design of a scanning electron microscope sample stage and the application of scanning transmission imaging, and in particular to the application of a device for obtaining scanning transmission imaging using an E-T type secondary electron detector in scanning transmission imaging.

Background technique

Scanning electron microscopy is often used to characterize the morphology structure and components of solid materials or quasi-solid materials, and has been successfully applied to many fields such as materials science, life sciences, semiconductor industry, and geological science.

At present, the most complete scanning electron microscope is usually equipped with an in-column secondary electron detector, a backscattered detector and a sample chamber Everhart–Thornley (E-T) type secondary electron detector for high-resolution surface morphology and composition. Observation of structure and high three-dimensional morphology. In addition, some high-configuration scanning electron microscopes are also equipped with high-cost retractable semiconductor scanning transmission probes for transmission electron signal imaging. However, the retractable semiconductor scanning transmission probe has problems such as high equipment cost, cumbersome operation, poor operational safety, poor time resolution, and can only work under 10-30kV conditions. Therefore, it is very urgent to develop a low-cost, easy-to-operate, high-temporal-resolution low-pressure transmission electron imaging method, but it is also a challenge.

The E-T secondary electron detector is a detector installed in the sample chamber and attracts secondary electron signals by adding a positive bias voltage to the detector surface. It is a standard detector for all scanning electron microscopes. The technology is mature. At present, there are few reports on the use of E-T secondary electron detectors for scanning transmission imaging, especially studies that can perform scanning transmission imaging under low voltage conditions below 5kV.

Contents of the invention

In order to solve the above problems, the present invention discloses the use of E-T type secondary electron detectors to obtain scanning imaging fixtures and methods thereof. By hindering the E-T detector from detecting secondary electrons, the scanning transmission imaging effect is obtained under low voltage conditions. The method described has simple process, good imaging effect and strong repeatability, and is suitable for various scanning electron microscopes.

A scanning imaging fixture is obtained using an E-T secondary electron detector, including a first component, a second component, screws and a copper mesh sample, the second component is provided with a row of locking holes and a row of grooves; the second component is provided with a row of locking holes and a row of grooves; One component is provided with sample placement slots, wherein copper mesh samples are placed on each of the sample placement slots, and screws pass through corresponding locking holes to fix the second component on the top of the first component.

A further improvement of the present invention is that: the bottom of each groove is provided with a convex ring; each convex ring snaps into place with the sample placement groove; and the aperture of each groove gradually decreases from top to bottom.

A further improvement of the present invention is that nails or columns are installed at the bottom of the first component.

The method of obtaining scanning transmission imaging using an E-T secondary electron detector is characterized by: including the following steps:

Step 1: Place the copper mesh sample on the sample placement slot of the fixing device on the first component; fix the second component on the first component through screws;

Step 2: Place the fixture with the copper mesh sample in Step 1 as close to the bottom of the objective lens pole piece as possible, and use the E-T secondary electron detector for imaging;

Step 3: Increase the distance between the fixture and the bottom of the objective lens pole piece, and use the E-T secondary electron detector to obtain secondary electron imaging or mixed signal imaging.

Component contrast imaging is obtained using an in-column backscattered electron detector.

During imaging, the situation in the sample chamber can be observed in real time through infrared cameras.

In the present invention, the copper mesh sample is fixedly installed in the device through screws. Through the groove depth design on the second component and the smaller working distance, the detection and collection of secondary electrons by the E-T secondary electron probe is suppressed, and the transmission electrons below the sample are collected to achieve the purpose of scanning transmission imaging.

The object of the present invention is to provide a method for obtaining scanning transmission imaging using an E-T type secondary electron detector. The method uses a designed grooved copper mesh sample stage, which can be seen in Figures 1 to 10. By blocking the E-T detector from detecting secondary electrons, the scanning transmission imaging effect is obtained under low voltage conditions. The method process It is simple, has good imaging effect and strong repeatability, and is suitable for various scanning electron microscopes.

Beneficial effects of the present invention: the grooved copper mesh sample stage is designed, and the scanning transmission imaging effect is obtained under low voltage conditions by suppressing the detection of secondary electrons by the E-T detector. The process is simple and does not require the optical path and vacuum of the electron microscope itself. The system has been modified to achieve excellent imaging results and strong repeatability, and is suitable for various types of scanning electron microscopes. The low-voltage scanning transmission imaging effect of the device and the imaging effects of other detectors were investigated. Compared with commercial scanning transmission detectors, the imaging method of the present invention can perform scanning transmission imaging at a lower voltage, and the time resolution is better than that of commercial scanning transmission detectors. Compared with light-sensitive commercial semiconductor detectors,

Description of the drawings

Figure 1 is a schematic diagram of the assembled scanning transmission imaging device according to the present invention, a top view.

Figure 2 is a schematic diagram of the assembled scanning transmission imaging device according to the present invention, a side view.

Figure 3 is a half-section view of the scanning transmission imaging device after assembly according to the present invention, direction one.

Figure 4 is a half-section view of the device for scanning transmission imaging according to the present invention after assembly, in the second direction.

Figure 5 is an exploded view of the scanning transmission imaging device of the present invention.

Figure 6 is a top view of assembly 1 in Figure 1 .

Figure 7 is a bottom view of assembly 1 of Figure 1 .

Figure 8 is a half-section view of the assembly 1 in Figure 1 .

FIG. 9 is a top view of assembly 2 in FIG. 1 .

Figure 10 is a bottom view of assembly 2 of Figure 1 .

Figure 11 shows the imaging of Nb ₂ O ₅ /graphene composite material under the condition of 800V by scanning transmission imaging according to the present invention.

Figure 12 is a mixed signal imaging of Nb ₂ O ₅ /graphene composite material obtained using the device of the present invention at a working distance of 9.9mm.

Figure 13 shows the secondary electron imaging results of the Cu@C composite material using the device of the present invention and using the secondary electron detector in the lens barrel.

Figure 14 shows the results of backscattered electron imaging of Cu@C composite materials using the device of the present invention and using a backscattered electron detector in the lens barrel.

Figure 15 is a schematic diagram of a device suitable for scanning transmission imaging of a Japanese electronics brand electron microscope, top view.

Figure 16 Schematic diagram of a device suitable for scanning transmission imaging of a Japanese electronics brand electron microscope, bottom view.

Figure 17 Schematic diagram of the device suitable for scanning transmission imaging of Hitachi brand electron microscope, side view.

Figure 18 is a setup flow chart of the present invention.

Detailed ways

The present invention will be further clarified below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. It should be noted that the words "front", "back", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings, and the words "inside" and "outside" ” refers to the direction toward or away from the geometric center of a specific part, respectively.

This embodiment provides a scanning imaging fixture and method using an E-T secondary electron detector.

The structural schematic diagram of the scanning imaging fixture using the E-T secondary electron detector can be seen in Figures 1 to 10. As can be seen from the figure, it includes a first component 1, a second component 2, screws 3 and a copper mesh sample 4. The second component 2 is provided with a row of locking holes 5 and a row of grooves 6; the first component 1 is provided with sample placement slots 7, wherein the copper mesh sample 4 is placed on each of the sample placement slots 7, The screws 3 pass through the corresponding locking holes 5 to fix the second component 2 on the top of the first component 1 .

Through the design of the groove 6 with a depth of 1.8mm on the second component 2 and the smaller working distance, the detection and collection of secondary electrons by the E-T secondary electron probe is suppressed, and the transmitted electrons below the sample are collected to achieve scanning transmission. imaging purposes.

Example 1 E-T secondary electron detector scanning transmission imaging.

Place the installed fixture in the scanning electron microscope and adjust the working distance to about 3.2mm. At this time, the top of the device is about 1.4mm from the bottom of the objective lens pole piece. At this time, the ET-type secondary electron detector can be used to obtain scanning transmission imaging of the Nb ₂ O ₅ /graphene composite material under low voltage conditions of 800V (as shown in Figure 11).

Embodiment 2 E-T type secondary electron detector performs mixed imaging of secondary electrons and transmitted electrons.

Place the installed fixture in the scanning electron microscope and adjust the working distance to about 9.9mm. At this time, the top of the device is about 8.1mm from the bottom of the objective lens pole piece. At this time, the ET type secondary electron detector detects a mixed signal of a certain proportion of transmitted electrons and secondary electron signals on the upper surface. As shown in Figure 12, the mixed signal imaging of Nb ₂ O ₅ /graphene composite obtained under 5kV conditions.

Example 3 Imaging of the secondary electron detector in the lens barrel.

Place the installed fixture in the scanning electron microscope and use the secondary electron detector in the lens barrel to perform secondary electron imaging. As shown in Figure 13, the surface morphology image of the material can be obtained.

Example 4: Imaging with a backscattered electron detector in the lens barrel.

Place the installed fixture in the scanning electron microscope and use the backscattered electron detector in the lens barrel to perform backscattered electron imaging. As shown in Figure 14, the composition contrast imaging of the material can be obtained.

Embodiment 5: Simply modify the first component 1, as shown in Figures 15 and 16, and install it on a Japanese electronics brand electron microscope

The scanning transmission imaging fixture using the E-T secondary electron detector below the first component 1 in Figure 1 is installed on a JEOL brand electron microscope, and the sample chamber secondary electron detector is used for imaging.

Example 6: Simply modify the first component 1 and install it on a Hitachi brand electron microscope

Replace the nails under the first component 1 in Figure 1 with M4 internal threads, as shown in Figure 17, install it on a Hitaichi brand electron microscope, and use the sample chamber secondary electron detector for imaging.

The E-T type detector used in this embodiment is resistant to light interference and can observe the situation in the sample chamber in real time through an infrared camera during imaging. The groove-type device of the present invention has the advantages of low price, simple operation, and can install 6 copper mesh samples at a time, and is expected to replace the commercial tungsten filament scanning transmission accessory. At present, it has not been reported that the E-T type secondary electron detector of the present invention can obtain low-voltage scanning transmission imaging, and it has important application prospects in the field of scanning electron microscope transmission imaging.

The technical means disclosed in the solution of the present invention are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims (5)

1. Use the E-T type secondary electron detector to obtain a scanning transmission imaging fixture, which is characterized by: including a first component (1), a second component (2), screws (3) and a copper mesh sample (4), as described The second component (2) is provided with a row of locking holes (5) and a row of grooves (6); the first component (1) is provided with a sample placement slot (7), in which the copper mesh sample (4) Place it on each sample placement slot (7), where the screw (3) passes through the corresponding locking hole (5) to fix the second component (2) on the top of the first component (1); each The bottom of each of the grooves (6) is provided with a convex ring (8); each of the convex rings (8) is snap-fitted with the sample placement groove (7); the bottom of each of the grooves (6) is The aperture gradually decreases from top to bottom. 2. The fixing device for obtaining scanning transmission imaging using an E-T secondary electron detector according to claim 1, characterized in that: the vertical linear depth of the groove (6) is 1.8 mm. 3. The fixing device for obtaining scanning transmission imaging using an E-T secondary electron detector according to claim 1, characterized in that nails or cylinders are installed at the bottom of the first component (1). 4. The method for obtaining scanning transmission imaging using an E-T type secondary electron detector according to claim 1, characterized in that: it includes the following steps: Step 1: Place the copper mesh sample (4) on the sample placement slot (7) of the first component (1) of the fixture; fix the second component to the first component (1) through screws (3) superior; Step 2: Raise the fixture with the copper mesh sample (4) in Step 1 to a distance less than or equal to 3.5 mm from the bottom of the objective lens pole piece, and use the E-T secondary electron detector to perform imaging; Step 3: Adjust the distance between the fixture and the bottom of the objective lens pole piece to less than or equal to 10 mm, and use the E-T secondary electron detector to obtain secondary electron imaging or mixed signal imaging. 5. The method of using an E-T secondary electron detector to obtain scanning transmission imaging according to claim 4, characterized in that the backscattered electron detector in the lens barrel is used to obtain component contrast imaging.