[ENG] [Tech.] SEM & EDS

[ENG] [Tech.] SEM & EDS

 

=====SEM & EDS=====
SEM (Scanning Electron Microscopy) is a scanning electron microscope and EDS (Energy-Dispersive X-ray Spectroscopy) is an X-ray spectroscopic analyzer. SEM can take high-esolution images, and EDS can determine the elemental composition and amount of a material.

=====SEM & EDS principle=====
SEM is an equipment that directly shoots electrons on the sample surface to observe the microstructure using the electron total amplification method. It goes through the process of shooting electrons, collecting signals emitted from the sample surface, and generating images. EDS uses the phenomenon in which an electron beam generated by an SEM collides with atoms in a sample to emit X-rays. The frequency and intensity of these X-ays is analyzed to determine elemental composition and quantity. SEM shoots electrons and creates images, and EDS uses X-ray analysis to determine the composition of a material.
Both can be used simultaneously within the same instrument, allowing SEM to take images and EDS to determine the elemental composition of the area. SEM is an electron mass microscope, which creates images by detecting signals from the interaction of beams of electrons on the surface of a sample. SEM is an electron mass microscope, which works in a similar way to an electron optical microscope, but allows much greater detail of the surface of a sample. The SEM shoots a high-energy electron beam at the sample surface and detects the electrons scattered from the sample surface. The signal detected at this time contains information representing the surface shape and components of the sample, such as defects, crystal structure, and components. The signals detected in this way are transferred to a computer and output as images. SEM is mainly used to analyze materials such as solids, such as metals, ceramics, and electronic polymers. SEM is, of course, a total electron microscope, but it is used in various fields by supporting various modes.
For example, SEM provides a variety of analysis functions, such as X-ay analysis, electron density measurement, and electromagnetic wave measurement.
So why use SEM? This is because SEM can analyze the surface structure of a sample with very high resolution. SEM is used in various fields because it can analyze the surface shape, size, defects, crystal structure, and bonding state of microstructures in analyzing the structure and characteristics of surfaces. For example, SEM is used in materials science to analyze the structure and properties of matter, and in life science to analyze cellular structures. Therefore, SEM is one of the very useful analysis tools. The principle of operation of SEM is simple. SEM emits electrons from an electron gun, and these electrons are projected onto the specimen surface and either reflected or absorbed. In this process, reflected electrons and secondary electrons generated from the sample surface are collected, processed appropriately, and displayed as an image. Images can be acquired by adjusting the position of the electronic gun and the distance from the specimen. Electron firearms used in SEM are largely divided into large electron firearms and field emission electron firearms (FEG).
Large electron firearms use the principle of cathode photoelectron tube (CRT) to emit electrons, and FEG uses the principle of amplifying surface electrons to emit electrons. SEM using FEG can obtain high-resolution images, even when the distance between the sample and the gun is close. The image is created by collecting secondary electrons from colliding electrons and reflected electrons from the sample. Each of these electrons produces a different signal, which is collected to create an image. SEM collects these signals, processes them appropriately, and displays them as images. To explain the working principle of SEM in more detail, SEM focuses on the sample surface and collects electrons reflected from the sample surface by adjusting the total amount of electrons. These collected electrons are measured by a detector and converted into an image. In SEM, an electron optical lens is used to focus a beam of electrons. As the light beam strikes the surface of the sample, it collects electrons that are reflected from the surface. At this time, the number of electrons reflected from the sample surface depends on the shape and characteristics of the sample surface. In SEM, the amount of electrons reflected from the sample surface can be controlled by controlling the total amount of electrons. This allows high-resolution images to be obtained by collecting electrons only at specific points on the sample surface. The collected electrons are measured by a detector and converted into an image. Most SEMs use a photoelectric detector to measure the collected electrons. The photoelectric detector converts the collected electrons into photons for measurement, which enables more accurate and high-quality images to be obtained.

SEM generates an image by generating electrons in an electron gun, sending a beam to the sample surface as mentioned before, and then catching electrons that are reflected or scattered from the sample with a detector.
This working principle is similar to that of electron optics (microscopy), but the difference is that SEM generates images by generating electrons and shooting them directly at the sample surface. Unlike optical microscopy, like electron optics, SEM directly examines the surface of a sample, so it has a much higher resolution than optical microscopy. In addition, SEM can cause structural changes or damage to the surface of the sample due to electrons colliding with the accelerating voltage, but these side effects are reduced because it operates in a non-contact manner with the sample rather than direct beam collision. For this reason, SEM is very useful for the analysis of nanoscale objects. To create images that reveal the presence of specific atoms or molecules, SEM uses beams of electrons. The electron beam used in SEM is generated through thermionic emission, and the energy of the electron beam is modulated by the voltage of the electrons generated in the electron source. A beam of electrons is focused through an optical lens onto the sample surface, and the electrons reflected off the sample surface are returned to the detector and used to create an image.

=====SEM structure=====
SEM is largely composed of an electro-optical part and a detection part.
The electro-optical part consists of an electronic light source, a specimen and an optical lens, and a computer control unit that controls the electron beam between the optical lenses. The detection part consists of devices that detect various signals emitted by electron beams interacting with the specimen. The electron light source of SEM mainly uses thermionic gun which uses thermionic emission. It operates on the principle of generating electrons using a heating wire. The electrons generated from the electron light source are focused by an optical lens having a high voltage, and then emit various signals while interacting with the specimen. The signals emitted at this time are detected by devices that detect various signals in the SEM. Representatively, there are primary electrons, secondary electrons, inverse electrons, and of course electrons, and these signals can be used to analyze the surface shape, composition, crystal structure, electrical and magnetic properties of a sample. This beam of electrons interacts with the sample surface and detects the various signals that arise. These signals appear in various forms depending on the interaction of the electron beam with the sample, and in the SEM, these signals are collected by appropriate detectors, converted into images, and displayed.

 

=====SEM Type=====
SEM is basically an electron optical microscope, a technique for imaging superficial features of the surface of a specimen. The types of SEM can be largely classified according to the difference in field magnification according to the optical method and the type of detector. SEM classification according to differences in field magnification
1.Optical electron microscopy (OEM) combining optical microscopy and SEM: This method acquires high-resolution images with SEM after observing the overall shape of the specimen with an optical microscope.
2.Focus Ion Beam SEM (FIB-EM): This method acquires images by shifting the focus in the SEM, processes the sample with the FIB, and inspects it in the SEM.
3. High Resolution SEM (HRSEM): SEM with a higher resolution than conventional SEM, made possible by improvements in optical conditioning and optical lenses, and advances in integrated circuit technology.
SEM Classification by Detector Type
1.Everhart-Thornley Detector SEM (ET-SEM): This is a commonly used SEM detector that acquires images by collecting high-energy electrons that generate positrons.
2. Backscattered Electron Detector SEM (BSE-SEM): When electrons pass through the material, only a small number of electrons are directly scattered, and the rest interact with the material to detect the returned electrons and acquire an image.
3. Dual Detector SEM (DD-EM): Using two or more detectors, the surface and interior of the sample are observed simultaneously and images are acquired.
4.Field Emission Detector SEM (FE-SEM): The FE-SEM uses fiber-ike optical conditioning to acquire images from thermionic emission.
Representative detectors of SEM include a concentrating electron detector (SE), a backscattered electron detector (BSE), and an X-ray generation detector.

Each detector detects a different signal depending on the sample's interaction with the electron beam.
One of the characteristics of SEM is its high resolution.
Since the SEM detects various signals caused by the interaction of electron beams with the sample, very high resolution images can be obtained using them. Also, unlike an optical microscope, SEM can measure the surface shape or height of a sample.
Next, SEM is a non-destructive analytical technique.
The sample is not destroyed during the process of surface observation or composition analysis with SEM.
Therefore, SEM has the advantage of obtaining images with very high resolution and resolution while preserving the sample to be analyzed. In addition, SEM can analyze a variety of samples. Since SEM uses relatively low-energy electron beams that do not cause electrical discharges in air, a wide variety of samples can be analyzed in air. In addition, since the SEM can analyze samples even in a high vacuum environment, analysis of various types of samples is possible.

=====What is EDS?=====
Energy dispersive X-ray spectroscopy (EDS) is one of the analytical techniques used with SEM.
In the SEM, X-rays are generated from the sample surface by shooting electrons at the sample surface and collecting back-stresses from the sample surface. Since the X-rays generated in this way have a unique wavelength for each element, the elemental composition in the sample can be determined by analyzing the wavelength of the X-rays.
EDS analysis uses the principle of X-ray generation and detection, and is a method of identifying the elemental composition within a sample by analyzing the X-ray energy spectrum collected from a spectrometer. For analysis, the SEM uses electrons to generate X-rays on the sample surface.
Because these X-rays have a unique energy for each element, the elemental composition within the sample can be determined by analyzing the X-ray spectrum collected from the spectrometer.
EDS requires the object to be analyzed to be exposed on a surface, which is usually a solid or powder sample. Because EDS is used in conjunction with SEM, SEM images and EDS analysis can be combined to determine the surface morphology and chemical composition of a sample together. EDS is widely used for chemical composition analysis in various fields, mainly in materials science, geology, and chemistry. EDS is a technique for analyzing the elemental composition of a sample using an X-ray spectrometer.
EDS is often used in conjunction with SEM, which shoots electrons at the surface of a sample and measures the X-rays emitted from the sample to determine its elemental composition.
In EDS, electrons are fired at a sample and atoms absorb them, releasing energy as the electrons in the atoms move to new orbits. This released energy occurs in the form of X-rays and is measured by the EDS to determine the elemental composition.
EDS is used in various fields. For example, in the field of materials research, it is used to analyze the elemental composition of various alloys and identify their properties. In chemistry, it is also used to infer reaction pathways by analyzing the products of chemical reactions.

 

=====EDS principle=====
EDS (Energy Dispersion Spectrum) is one of the analysis techniques used with SEM. It is a technique to determine the composition of elements by analyzing the X-ray spectrum generated by the interaction with electrons emitted from the sample surface. In EDS, electrons generated in the SEM are projected onto the surface of the sample, causing atoms within the sample to interact with and activate electrons in the mineral material. These activated atoms rapidly return to their original state, emitting X-rays.
The X-rays emitted in this way have a specific energy corresponding to each atom, and by analyzing this energy, the corresponding element can be identified. EDS analysis determines how much of each element is present in a sample by measuring the X-ray energy dispersive spectrum.
These analyzed spectra can be used to identify the elemental composition using a variety of software, thereby determining the chemical composition of the sample. To explain the working principle of EDS in more detail, first, when an electron beam is directed at the sample surface, the atoms inside the sample absorb electrons, emit new electrons, and are placed in various energy levels, as described previously. At this time, the emitted electrons are directed to a detector surrounding the sample, and in this process, the detector measures the electron's kinetic energy to determine which atom the electron came from and what kind of atom it is.
In EDS analysis, information about these electron-atom interactions is interpreted as an X-ray spectrum.
An electron from a specific atom emits a specific X-ray energy, and this energy has a unique value depending on the electronic structure of the corresponding atom. By analyzing the X-ray spectrum detected through this, atomic structure and component information inside the sample can be identified.
EDS analysis is often used in combination with SEM, and in this case, after examining the surface of the sample with SEM, it is utilized in a way that EDS is used to analyze the components of the area.

 Through this, it is possible to analyze the components inside the microscopic sample, which is used in various fields. EDS is an X-ray emission spectroscopy analyzer, a sample-to-sample analysis technique like SEM.
An electron beam is irradiated on the sample surface to generate X-rays, and the X-rays are spectroscopically analyzed to determine the elemental composition of the sample. EDS can accurately locate the X-ray emission positions on the sample surface, and measure the elemental content and distribution at each position.
The basic principle of EDS analysis is that elements that often emit characteristic X-rays occur when they interact with certain materials. 

As the electron beam interacts with the sample, X-rays are emitted. Each of these X-rays has a specific energy and specific frequency, and by analyzing them spectroscopically, the elemental composition of the sample can be determined.
EDS is primarily used for compositional analysis of solid samples and is used in conjunction with SEM. While irradiating the electron beam of the SEM, the surface of the sample is scanned, and the elemental composition of the specific area is analyzed through the scanned image. EDS analysis is used in various fields because it can measure not only elemental analysis but also bonding states and bonding energies.

=====Specimen preparation method=====
Depending on the size and shape of the sample that can be observed in SEM, there are various sample preparation methods.For example, most solid samples are used either by smoothing the surface into small chunks, or by polishing the surface to a shine and then coating it with a metal to make it observable under the SEM. In addition, equipment such as a suitable sample holder or sample cleaner is required when observing liquid or gas samples in the SEM.
In addition to this, sample preparation is one of the important topics in the SEM field, and appropriate sample preparation methods should be selected according to the type and size of the sample. In the field of microscopy, AI technology has recently been utilized.

For example, research is underway to utilize AI in tasks such as analyzing SEM images to understand and classify the structure and properties of materials. Through this, analysis tasks that previously required a lot of time and human resources can be automated, and more accurate and efficient analysis is possible. In addition, applications such as predicting the properties of new materials by developing an AI model that learns the properties of materials by analyzing SEM images are being studied. An SEM consists in most cases of an electron optical microscope, in which a beam is directed at a sample to produce an image of the surface, which is collected along with the signal that bounces off the sample.
In this process, interaction between the sample and the beam occurs, and through this, various information can be obtained.
SEM offers very high resolution in producing images, which allow detailed characterization of materials. In addition, SEM is a non-destructive analysis method, and it is possible to analyze various samples.
For example, when analyzing biological samples, SEM can determine the shape, size, and surface structure of cells.
SEM is also very useful for studying the structure and properties of nanomaterials.
An electron microscope specimen is used to convert a target material into an oxide, fasten it, and irradiate it with an electron beam. Therefore, the process of making a sample into an oxide is the core of the specimen fabrication process.
Specimen fabrication usually includes the following steps:
-Sample selection: The sample must have a size and thickness that can be observed using an electron microscope. In addition, it is ideal if the physical properties should be stable and the tissue structure should be clean without microstructures or defects.

-Sample Cutting: Cut the sample into a size that can be observed under an electron microscope. 

At this time, the thickness of the sample is determined by the electron density of the electron beam used in the electron microscope.
-Sample flattening: It flattens the sample to make it suitable for electron beam irradiation. Techniques such as plane polishing and plane smoothing are used in this process.
-Chemical treatment of the sample: Converts the sample to an appropriate oxide state that can be used in SEM. 

In this process, the surface of the sample is converted into an oxide state by using an appropriate chemical agent to cause an oxidation or reduction reaction.
-Sample fastening: Fix the sample to the SEM sample holder. Usually, an electronically conductive adhesive is used to fix the sample to the sample holder, and some samples may be subjected to electrode treatment for this purpose.
-Coating of the sample: When using SEM, a coating can be applied to protect the surface of the sample and 

increase the electronic conductivity. Usually, the sample is coated with gold or a gold-palladium alloy.
The SEM specimen manufactured through the above process shows appropriate reflection and absorption when the electron beam is irradiated on the sample surface, so high resolution and clear images can be obtained.

 

=====Precautions for specimen preparation=====
-Contamination prevention: When manufacturing specimens, work must be done in a clean state.

Dust, organic matter, etc. can interfere with viewing the sample surface in the SEM.
-Avoidance of electron beam absorption

: When observing a sample in the SEM, it is necessary to prevent the absorption of electron beams. To this end, a metal coating with good conductivity may be applied to the surface of the sample, or a coating may be applied to protect the surface from dust.
-Sample size: The sample size observable in SEM is usually no more than 1 cm x 1 cm x 1 cm.
Therefore, when fabricating a specimen, it must be made in an appropriate size.
-Thickness: When observing a sample in SEM, the thickness of the sample must be within a certain range. To do this, it is necessary to make appropriate thin slices or to make samples with uniform thickness during the specimen fabrication process.
-Shape

: Depending on the shape of the sample to be observed in the SEM, an appropriate specimen fabrication method should be selected.
For example, for surface observation, samples with flat and clean surfaces must be fabricated.
Observing these precautions and manufacturing specimens can yield more accurate and useful SEM observation results.

=====Quality improvement plan=====
- Proper sample preparation: Proper sample preparation is necessary to improve SEM image quality. This can improve the resolution and clarity of SEM images by keeping the surface of the sample clean, removing impurities or isolating microstructures.
-Proper setting of accelerating voltage and amount of light

: The clarity and contrast of SEM images are greatly affected by the settings of accelerating voltage and amount of light.
The clarity and contrast of SEM images can be optimized by selecting the appropriate accelerating voltage and light intensity.
-Appropriate filtering: Appropriate filtering techniques can be used to remove noise from SEM images and improve image resolution. This is very useful for improving image quality.
-Using an appropriate emission electron detector

: The emission electron detector plays a very important role in image acquisition in SEM. The resolution and intelligibility of SEM images can be improved by using an appropriate emission electron detector.
-Fair comparison: 

When comparing SEM images, the conditions or parameters under which the images were acquired must be the same. For fair comparison, conditions or parameters must be kept constant when acquiring SEM images. 

-Correct image post-processing: Post-processing of SEM images is very important to improve image quality.

 SEM images can be improved by performing appropriate image post-processing. 

These methods can improve SEM image quality.
-In EDS analysis,

 the analysis quality can be improved by keeping the surface of the sample clean and performing appropriate background noise correction. This requires appropriate pretreatment to make the sample surface clean.
In addition, interpretation and correction of X-ray spectra are important in EDS analysis. 

This requires efficient calibration with appropriate software.
In addition, in order to improve the quality of SEM images, appropriate sample preprocessing and SEM condition settings are required. In order to improve the resolution of SEM images, it is necessary to set SEM conditions such as appropriate accelerating voltage, amount of light, and sight.
In addition, appropriate sample surface treatment and SEM condition settings are required to increase the contrast of SEM images.
In addition to this, various techniques and methods are being developed to improve the quality of SEM images.
For example, optical sectioning microscopy technology has recently been developed and can be used to increase the resolution of SEM images.

In addition, using artificial intelligence technology, automatic analysis and correction of SEM images is becoming possible. Another way to improve SEM image quality is to optimize the characteristics of the sample surface. This is because the characteristics of the sample surface directly affect the SEM image quality. For example, it is important to keep the sample surface clean and flat. This can be done by cleaning the sample surface, correcting unevenness, or surface treatment.
It is also important to maintain the high electron density required to improve the resolution of SEM images.
For this purpose, the electron density can be increased by adjusting the conditions of SEM.
For example, the electron density can be adjusted by adjusting conditions such as the accelerating voltage, light intensity, light diameter, and light center position of the SEM.
You can also improve image quality by taking advantage of the high resolution of the SEM's camera or detector. Finally, image post-processing methods can also be used to improve the quality of SEM images.
To do this, image processing software can be used to remove noise, emphasize borders, adjust color, and adjust contrast.
This image post-processing method is effective in improving the quality of SEM images.
Another method of improving SEM image quality is sample preprocessing.
Since SEM image quality can vary greatly depending on the state of the sample, pre-processing can remove impurities or smooth the surface of the sample, for example.
For example, if the surface of a sample is rough or corroded, the surface is polished or flattened to make it flat. Alternatively, the surface of the sample may be coated with a slippery surface to minimize image distortion caused by electron beams bouncing off the surface.
There are also ways to optimize SEM conditions to improve SEM image quality.
SEM conditions include accelerating voltage, electron intensity, working distance, detector position, and adjustments using standardized materials. For example, the higher the accelerating voltage, the higher the resolution of the SEM image, but the higher the possibility of damaging the surface of the sample, so it is important to find the optimal conditions.
In addition, image processing can improve SEM image quality.
Image processing includes operations such as removing noise from SEM images, improving contrast, or increasing sharpness.
For example, you can improve SEM image quality by filtering images, adjusting brightness and contrast, and adjusting color balance. Another way to improve SEM image quality is to change the sample processing method.
In SEM, how samples are processed can affect the resolution, contrast, and noise level of SEM images.
Water droplets or contaminants on the surface of the sample can reduce the sharpness of the image, and for high surfaces the contrast of the SEM image can be reduced. Therefore, it may be useful to change the processing method of samples to improve SEM image quality. Keeping the sample surface clean and applying a special coating to the surface may also help.
In addition, the sharpness and contrast of SEM images can be adjusted by changing various conditions, such as cooling or heating the sample. Another way is to apply image processing techniques. SEM images are sometimes noisy and lack sharpness. To address this, you can enhance images using techniques such as image filtering, color equalization, and color inversion. It is also possible to extract and analyze information from SEM images using image analysis software.
Another way to improve SEM image quality is to increase the stability of the probe stage.
Since SEM images are greatly affected by the stability of the probe stage, increasing the stability of the stage improves the quality of the image. To this end, the stage is equipped with a charging and discharging device to prevent vibration and a stabilization device using a magnetic field. In addition, the quality of the image can vary greatly depending on the electrode fabrication method of the SEM sample.
Depending on the surface treatment of the electrode, the choice of contact material, etc., the electrode must be manufactured in a state suitable for SEM.
In addition, since the position and direction of the sample and the shooting conditions also affect the quality of the image when taking SEM images, optimizing these conditions is also important for improving image quality. Finally, the post-processing of SEM images also has a great impact on image quality. In post-processing, you can improve the sharpness and resolution of an image by adjusting the contrast or brightness of the image, removing noise, and so on. Therefore, SEM image analysis requires a good understanding of image post-processing.

 

=====SEM, EDS application scope and strengths and weaknesses=====
SEM is used for microstructure observation, surface analysis, and tissue analysis.
EDS is used to determine the composition and amount of elements in a sample, and is widely used in materials science, chemistry, and geology. However, SEM and EDS may have limitations depending on the electron density or X-ray emission of the sample.
SEM has applications in various fields. The most common application is in materials science.
SEM can be used to analyze the microstructure and imperfections of materials, which helps to understand and improve the mechanical, electrical, and optical properties of materials.
SEM is also widely used in the semiconductor industry for quality inspection and process improvement. SEM also plays an important role in life sciences. SEM can be used to study cell and tissue structures, or to analyze the surface shape and structure of organisms. Through this, it can be used to understand the internal structure of a cell or the function and physiological characteristics of an organism, and to develop drugs. In addition, in the environmental field, SEM can be used for environmental monitoring and ecosystem conservation by analyzing pollutants such as air and water quality, and studying microbial communities and optical characteristics. SEM is also used in cultural heritage fields such as archeology, arts and crafts. It can be used for preservation and restoration by analyzing the microstructure or surface condition of cultural properties.
As such, SEM is being used in various fields, and it is expected that it will be used in more diverse fields with more advanced technology in the future.
-Standard SEM (Standard SEM) Standard SEM is the first commercially successful SEM, 

has high magnification and resolution, and is the most commonly used SEM. A standard SEM not only displays information on a surface as an image, but can also analyze the chemical composition of a surface using X-rays emitted from it.
-High-Resolution SEM (HRSEM) Ultra-high-resolution SEM has higher resolution than standard SEM and is used to analyze bio-nano materials such as metal nanoparticles, peptides, and proteins. Ultra-high-resolution SEMs use electro-optical lenses to obtain more sophisticated images.
-Dimensional Measurement SEM (Dimensional Measurement SEM) Dimensional Measurement SEM 

uses the same technical principles as standard SEM, but allows more precise measurements. This SEM accurately measures real-world size and shape, and provides zoom factors in terms of images.
-Transmission SEM (T-SEM) Transmission SEM is a SEM that can analyze the internal structure of a material 

by measuring the thickness of the sample material or incident electrons at atomic thickness.
T-SEM is similar to TEM because it is a method of shooting electrons at a sample to obtain an image of the inside.
-Ultra-Precision SEM (Ultra-Precision SEM) Ultra-precision SEM is a SEM that provides precise position control and large magnification to observe structures at the nano level.
Ultra-precision SEM is applied to the measurement of microstructures at the nanoscale, connections, etc. 

The advantage of SEM is that it can take high-resolution images. Also, after taking an image with SEM, 

EDS can determine the elemental composition of the area.

 However, the downside of SEM is that it is difficult to see information inside the sample. 

The advantage of EDS is that it can determine the composition and elemental composition of matter.
However, the downside of EDS is that it can check the elemental composition, but it is difficult to know the chemical state or bonding state of the elements.

=====Analysis of component information, image formation information, structural information=====
-How to acquire component information

: There are two major methods of analyzing the component information of a substance: chemical analysis and physical analysis. Chemical analysis is to find out the components, elements, and chemical symbols of substances. 

This can be performed by methods such as infrared spectroscopy, mass spectrometry, atomic absorption spectrometry, electrophoresis, and liquid chromatography.
Physical analysis is to analyze the physical properties of a material, and is a method of measuring ionic conductivity, thermal expansion coefficient, absorptivity, and rotational inertia.

-How to acquire crystal phase information

: Crystal phase information indicates how a substance is crystallized.
Crystalline phase information of materials can be analyzed using techniques such as X-ray diffraction, electron diffraction, and Raman spectroscopy.

-How to acquire structural information

: Structural information of a substance indicates which atoms the substance is composed of and the type of bonding between atoms. 

These techniques include X-ray crystallography, electron microscopy, NMR analysis, infrared spectroscopy, 

and mass spectrometry. 

By acquiring and analyzing component information, crystalline phase information, and structural information using these methods, the characteristics of substances can be identified and used for utilization and research of substances. Methods for obtaining structural information include X-ray diffraction analysis, NMR analysis, 

and electron density distribution analysis. X-ray diffraction analysis is one of the methods to find out the crystal structure of a material. 

It is a technique to determine the three-dimensional structure of a crystal by shooting X-rays at a crystal and measuring the angle and 

intensity of the diffracted X-ray.

NMR analysis is a nuclear magnetic resonance analysis technique that uses the magnetic properties of atoms in a molecule to identify molecular structures and interactions between molecules. Electron density distribution analysis is a method to determine the crystal structure by measuring the electron distribution, and is analyzed in a similar way to X-ray diffraction analysis. As a result, it is important to comprehensively utilize various analysis techniques to obtain component information, phase formation information, and structural information.

 

=====Other instruments and methods=====
-Atomic Force Microscopy (AFM) AFM is a microscopic microscopy technique in which a fine needle scans the sample 

surface to produce a high-resolution image. 

This technology is used in various fields such as biology, nanoscience, and medicine, 

and is also widely used to study proteins, DNA, biomolecules, and nanomaterials.
-Scanning Tunneling Microscopy (STM) STM is a microscopy technique that uses nanometer-sized electromagnetic waves to scan the surface of a sample to create an image. 

This technology is used in various fields such as semiconductor research, nanotechnology, and nanoelectronics.
-Transmission Electron Microscopy (TEM) TEM is a technology that creates an image by scanning a sample 

using electrons, unlike an optical microscope that uses light to create an image. This technology is used for nanomaterial structure analysis, crystal structure research, nanoparticle and biomolecule research, etc.
- X-ray Photoelectron Spectroscopy (XPS) XPS is a technology that analyzes the chemical composition of the sample surface using X-rays.
This technology is widely used in industry, materials research, chemical research, biology, etc.
-Energy-dispersive X-ray spectroscopy (EDX or EDS) EDX or EDS is a technique that analyzes the chemical composition of a sample in combination with an electron microscope. This technique is used in the study of a variety of materials, including metals, ceramics, and semiconductors, and in the analysis of biological samples.
-SIMS (Secondary Ion Mass Spectrometry): Releases ions from the sample surface and analyzes the distribution of elements inside the sample using ion mass spectrometry.
-Raman Spectroscopy Raman spectroscopy is a technique to determine the chemical composition of a sample by measuring changes in molecular vibrational energy. This technology is used in various fields such as nano-material research and research, chemistry, and life sciences.
Raman spectroscopy analyzes by measuring Raman scattering arising from irregularities in molecular vibration. When a sample is irradiated with laser light, molecular vibration occurs and the frequency of the light changes. By analyzing the frequency of this changed light, the molecular structure and composition of the sample can be identified. Because Raman spectroscopy has very high resolution, it is possible to analyze in detail the interactions between molecules, the shape and nature of bonds, and the crystal structure. In addition, analysis is possible regardless of the physical state of the sample, and since it is a non-destructive method, repeated measurements are possible without damaging the sample.
Raman spectroscopy is widely used in materials science, chemistry, and life sciences. In materials research, it is used in crystal structure analysis, single crystal analysis, and crystal growth research, and in the field of chemistry, it is used in analysis of reaction catalysts, molecular structure analysis, and chemical reaction mechanism research. It is also used in the life sciences for analysis of proteins, DNA, cells, etc.
The advantages of Raman spectroscopy are its high resolution, non-destructive analysis method, and its application in all states such as solid, liquid, and gas. However, the disadvantage is that the Raman scattering phenomenon is relatively weak, so the sensitivity may decrease depending on the concentration of reactants in the sample or the measurement time. In addition, there are cases where the surface of the sample needs to be removed during surface analysis due to poor surface sensitivity.
-XPS: XPS is an analysis method that uses an X-ray light source to emit electrons from the sample surface. This analysis method can analyze the chemical composition, chemical state, surface structure, etc. of a sample. XPS is applied to solid surface analysis, oxide film analysis, and distribution analysis of specific elements on the surface of a sample.
-TOF-SIMS: TOF-SIMS is a method for mass spectrometry of ions generated from the surface of a sample. This analysis method is applied to analyze the surface structure, chemical composition, and fine particles of the sample. TOF-SIMS is used in a variety of samples, including semiconductors, polymers, and biomaterials.
-FTIR: FTIR is an analysis method using infrared spectrum analysis. This analysis method can analyze the chemical composition and molecular structure by analyzing the vibration and bending of the molecules in the sample. FTIR is applied in various fields such as chemistry, life science, and food.
-XRD (X-ray Diffraction): This is an equipment to determine the crystal structure. The crystal structure is confirmed by shooting X-rays and analyzing the pattern of the diffracted X-rays. XRD is mainly used to analyze the crystal structure of materials. For example, it is used for crystal structure analysis of newly developed substances, minerals, drugs, etc.
-There is Electron Excitation X-ray Emission Spectroscopy (EXES). EXES is a method for analyzing the existence and chemical state of elements using electrons and photons. Electroluminescence spectroscopy uses a principle similar to EDS, but uses electrons to make elements emit light and analyze the emission spectrum. EXES is primarily used for solid surface analysis. For example, it can be used for structural analysis of newly developed oxide complexes or microstructure analysis of metals.
-There is Atomic Absorption Spectroscopy (AAS). AAS is widely used for elemental analysis and is particularly useful for concentration determination. This method calculates the concentration of an element by measuring the amount of energy absorbed by the element's atoms as they pass through the absorption line. AAS is primarily used to measure heavy metal concentrations in food, plants, and the environment. For example, AAS is used to measure the degree of metal contamination by analyzing metal-contaminated water.
-STEM (Scanning Transmission Electron Microscopy) is a technique that transmits electrons into a sample to observe the internal structure of the sample, combining the advantages of SEM and TEM. In STEM, electron optical lenses and beam collimators are used to focus an electron beam, concentrating the electrons into a very small area. As this focused electron beam passes through the inside of the sample, it is back-scattered to calculate the electron density distribution inside the sample. The main advantages of STEM are its high resolution and high spatial resolution. High resolution can achieve sub-nanometer spatial resolution by overcoming resolution limitations caused by imperfections in optical lenses used in electron microscopes such as SEMs and TEMs. In addition, high spatial resolution is possible because images are obtained by adjusting the size of the electron beam very small to interact with the sample surface. STEM is particularly useful for research on nanomaterials, structure and function of biological samples, and energy storage materials. STEM Application Scope and Limitations STEM is mainly used for research on nanomaterials, structure and function of biological samples, and energy storage materials. In particular, since STEM can measure the electron density distribution in a very small area, it is useful for studying the crystal structure, surface shape, physical properties, and catalytic reactions of nanomaterials. However, STEM cannot operate in air like SEM and TEM, so samples must be processed under vacuum. In addition, since the sample may deteriorate while interacting with the electron beam, it is difficult to acquire images of the sample in real time.
- Advantages and disadvantages of STEM
Advantages: Because it has high resolution and high spatial resolution, very accurate images can be obtained in the sub-nanometer region. Since the internal structure of electronic samples can be observed, it is very useful for research on nanomaterials, structure and function of biological samples, and energy storage materials.
Disadvantages: Sample preparation is time consuming and costly, as samples must be processed under vacuum. Samples can deteriorate while interacting with the electron beam, making it difficult to acquire images of the sample in real time, which can limit research. Compared to TEM, sample processing is more complicated, and more advanced techniques and expertise are required. This is required.
-FIB (Focused Ion Beam): This is a device that can cut and process nanomaterials using ion beams instead of electron beams.
-NMR analysis (Nuclear Magnetic Resonance)

: NMR is a method to determine the molecular structure using the characteristics of nuclear magnetic resonance in a molecule. When atomic nuclei in a molecule are exposed to a specific magnetic field, they emit electromagnetic waves with specific frequencies. By measuring this, the number and location of atomic nuclei in a molecule and the state of bonding can be identified.
NMR is mainly used for structural analysis of organic compounds. Examples for each analysis method are numerous.
For example, XRD is used for mineral analysis, ICP for metal element analysis, and Raman spectroscopy for chemical analysis. In addition, each analysis method may be used in conjunction with other analysis methods. For example, XRD and SEM are used together to analyze the crystalline structure and morphology of a material, or EDS and TEM are used together to determine the elemental distribution and structure within a material.

=====Explanation of types and manufacturers of SEM microscopes=====
The SEM microscope is a scientific instrument that uses an electron beam to observe the surface of a sample at high resolution.
SEM microscopes are mainly used in various fields such as material science, biology, and geology, and there are various types and manufacturers. Types of SEM microscopes that are typically used include Field Emission SEM (FE-SEM), Discharge SEM (Scanning Electron Microscope, SEM), and Electron Probe Micro Analyzer (EPMA).
FE-SEM is a microscope that produces and focuses images of a high-density electron field on the surface of a sample.
As a result, high-resolution images can be obtained. Representative manufacturers of FE-SEM include Zeiss, Hitachi, JEOL, and Tescan.

1. FEI Company FEI Company is one of the leaders in electron microscope related technologies and a global supplier of high-performance electron microscopes and Focused Ion Beam (FIB) solutions.
Since the early 2000s, FEI Company has been continuously innovating in the field of SEM-related technologies and has released a variety of SEM products. FEI Company's SEM product line includes Magellan, Helios, and Nova, and these products provide a variety of specifications and functions to meet various requirements such as sample size, complexity, and resolution.
2.Zeiss Zeiss is a world-renowned company in optics, electronics, mechanics and measurement systems.
In the SEM field, various models such as EVO, Ultra, and Merlin are available, which provide high-resolution images and analysis for a variety of SEM applications. In addition to SEMs, Zeiss also offers a range of high-performance electron microscopes, including FIB technology.
3.Hitachi Hitachi is one of Japan's leading multinational corporations, providing products in a variety of industries.
Hitachi's SEM product line includes the SU series, S-4800, and S-3000N, and provides additional analysis functions such as EDS analysis as well as high-resolution image acquisition.
4.Tescan Tescan is a Czech company that supplies SEM and FIB solutions.
Tescan's SEM product line includes MIRA, VEGA and LYRA, which provide high-performance imaging and analysis. Tescan also offers a variety of analytical accessories and software to meet the diverse needs of SEM analysis.

=====About FIB=====
FIB stands for Focused Ion Beam, and is an advanced analysis and processing technology that processes or manipulates materials using a focused ion beam. FIB is generally used together with SEM, and like SEM, images are created using ions. However, SEM uses electrons, and FIB uses ions to process or manipulate the surface of a sample. Since the ion beam has high energy, it can process the surface of the sample or remove material while impinging on the sample.FIB is utilized in various fields.The most common use is material processing in microelectronics and materials science.With FIB, you can create nano-level structures, manipulate microscopic structures inside samples, 

or study nanomechanisms. 

FIBs are also used to create nanodevices, machines, circuits, etc. that are experimentally created in laboratories.
Representative companies using FIB technology include the FEI company, JEOL, Hitachi, and Zeiss, which manufacture and sell FIB equipment. If you visit the websites of these companies, you can find technical specifications and various use cases for each equipment. FIB technology is being used in various fields.
For example, in the field of semiconductor manufacturing, FIB can be used to investigate defects in semiconductor chips or to fine-tune circuit patterns.
In addition, in the field of nanomaterial research, FIB can be used to create nanostructures or to investigate the physical properties of nanostructures.
In the field of biology, FIB can also be used to investigate the structure inside cells or probe biological samples. Equipment using FIB technology is manufactured by various companies. Representative manufacturers include FEI, Zeiss, Hitachi and Tescan. FIB equipment from these manufacturers each has its own unique features and functions, and can be selected according to research fields and applications. Thermo Fisher Scientific (FEI) is a leader in FIB-SEM technology and offers a range of FIB instruments such as the Helios and Helios G4 series. These products provide high performance suitable for a variety of applications and can be selected according to research fields and uses.
FEI's official website provides detailed product information and technical support.
Zeiss offers advanced FIB-SEM systems, such as the Crossbeam series, used in a variety of research fields. These instruments offer versatile capabilities for high-resolution imaging and analysis, allowing users to perform detailed manipulations on materials and biological samples. Zeiss' official website provides product information and technical support. Hitachi offers a variety of FIB equipment utilized in various industries. FIB-SEM systems such as the S-4500 and S-4800 series offer high resolution and advanced analytical capabilities, and are used in a variety of research fields. Hitachi's official website provides product information and technical support.

=====Fields of Utilization of FIB=====
FIB technology is being used in various fields. The semiconductor industry uses FIB technology to create experimental semiconductor chips, to find and fix defects, and so on. Also, in the field of nanotechnology, research is being conducted to create nanodevices using FIB technology.
In addition, in material research, FIB technology is used for analysis such as studying defects or microstructures inside materials. Because FIB technology has high precision and scalability, it is used in various fields. The FIB technology can be used in conjunction with various analysis technologies such as SEM and TEM, and has become a powerful tool applicable to various applications. FIB technology continues to evolve in recent years. In particular, nano-processing technology using FIB plays a key role in the field of nanotechnology. Recently, research on applying plasma technology to FIB technology is being conducted.
This minimizes damage caused by heating and ion collision during FIB processing, and improves processing speed and accuracy. Plasma technology can also be used in a variety of fields, such as sample surface treatment or cleaning of the inside of a measurement space.
As another development direction, a technology that uses He ions instead of Ga ions, which are ion sources used in FIB, is being researched.
He ions have the advantage of causing less damage and corrosion than Ga ions and are better suited for processing techniques such as soft landing. These technologies are expected to significantly improve the accuracy and efficiency of nano-machining. Companies that apply FIB technology include FEI, Zeiss, and Hitachi. You can learn more about FIB technology through these companies' sites.
Recently, FIB technology is applied in various fields.
For example, it is used in various fields such as nanomachines, optoelectronic devices, biomedical, materials and nanoelectronics fields.
In addition, various new technologies are being developed due to the development of FIB technology. For example, FIB-TEM coupled technology enables analysis at the atomic level, and FIB-SEM-TMA technology enables more accurate analysis by immobilizing the sample. In addition, since FIB technology requires high energy, it is difficult to apply in environments where energy supply is difficult. To solve these problems, a new technology called FIB-Plasma or P-FIB is being developed by combining FIB technology with plasma technology. P-FIB technology is evaluated as a more useful technology as it consumes less energy than FIB technology and can be applied to various samples. In addition, although Ga ions were mainly used in FIB technology, recently, technologies using Xe plasma ions are being developed.
Xe plasma ions have higher energy and current density than Ga ions, enabling more precise and faster sample processing. The recent development of FIB technology is further expanding its application possibilities in various fields. It is expected that more precise and faster FIB technology will be developed and used in various fields such as future nanotechnology and material research. The development of FIB technology is expected to be used not only in future nanotechnology and material research, but also in various fields such as semiconductors, electronic devices, energy, medicine, and life sciences. In particular, nanofabrication technology using FIB plays a very important role in nanoelectronics. Nano processing technology is required in various fields such as nano semiconductor manufacturing, nano material manufacturing, and nano sensor manufacturing.
Nanofabrication technology using FIB technology can create more sophisticated nanopatterns and can be used in various applications such as highly sensitive sensors, semiconductor devices, and functional nanostructures. FIB technology also plays a big role in life sciences. Creating nanoscale structures is important for understanding the structure and interactions of biological samples. To this end, FIB technology is also applied to the processing of biological samples, and is used to study tissue, proteins, and DNA inside cells.
FIB technology can also be utilized in the energy sector. It is possible to create nanostructures of various energy-related materials such as solar cells and fuel cells, and through this, it is possible to develop high-efficiency energy conversion devices. As such, FIB technology is developing into a technology that can be used in various fields, and it is expected that there will be application possibilities in more fields in the future.

=====FIB principle=====
FIB (Focused Ion Beam) is a technique that works on the same principle as SEM, but uses a focused ion beam instead of an ion beam to process and analyze a sample. Thus, FIB offers higher resolution and resolution than SEM, and provides greater depth and faster sample fabrication speed. One of the ways that FIB can be used to measure fast and large areas is FIB-SEM exploration.
FIB-SEM exploration slices the sample into FIB

 

=====Types of FIB (advantages and disadvantages)=====
- Xenon Plasma Focused Ion Beam (Xe PFIB)
- Gas Field Ionization Source (GFIS)
- Helium Ion Microscopy (HIM)
-Xenon Plasma Focused Ion Beam (Xe PFIB): Xenon Plasma Focused Ion Beam (Xe PFIB) is a method of cutting the sample surface using Xe atoms instead of the Gallium Ion Source commonly used in FIB systems.
Xe PFIB has high cutting accuracy and speed, so it can cut a large area of sample in a short time, and depth profiling and analysis of the sample are possible with high resolution of FIB image.
Advantages: High cutting accuracy and speed enable processing of large area samples in a short time Possess high resolution FIB image quality Applicable to various sample shapes and thicknesses
Disadvantages: Xe PFIB source is expensive and tends to be more expensive than other FIB sources Risk of adhesion and damage compared to samples
-Gas Field Ionization Source (GFIS): Gas Field Ionization Source (GFIS) is a FIB technology that processes samples by generating ionized particles using gas molecules.
Compared to Ga FIB, GFIS is known to cause less damage to the sample surface due to the lower energy of the ionized particles, resulting in reduced image resolution and sample-to-sample adhesion risk.
Advantages: Less damage to the sample surface due to the use of low-energy particles Reduced image resolution and risk of adhesion to the sample Disadvantages: Low load capacity compared to other FIB sources, limiting processing of samples with large surface areas Particle flux required for analysis Possible increase in analysis time due to low
-HIM Because the helium ion is used, the electron orbital size is small, so it can provide more detailed images than SEM.
In addition, since the mass of He ions is small, there is little risk of damaging the sample surface, allowing microfabrication with processing techniques such as FIB. It is also useful for detecting the chemical composition and defects of a sample by using the bright signal generated by the interaction of He ions with the sample. However, HIM technology also has some limitations.
For example, because He ions have a small mass, they cannot penetrate into the inside of the sample and are confined to the surface.
In addition, the effect of the impact wave on the sample due to the collision of He ions must be considered.
Finally, since HIM is still a relatively new technology compared to SEM, it may have limited usability compared to SEM. Because HIM uses He ions, it avoids the collisions and background signals that SEM produces. This provides higher image contrast and lower noise levels. In addition, HIM provides high resolution in thin samples and can image a higher layer depth than SEM. However, since HIMs do not take images of the entire sample, but only the scan area, it can be difficult to ensure representativeness of the sample. Additionally, Him's installation and operating costs can be relatively high. Compared to traditional SEM, HIM results in higher image sharpness due to very low-energy impurity emissions and sample damage.
HIMs also have ultra-high vibration operating times.
This prolongs the lifetime of high-mass samples and helps limit single-atom collisions. HIMs also use optics, which are primarily used with out-of-band detection (BSE). Unlike SEM, HIM captures images where the BSE is created, so it can capture images of all materials on the sample surface. However, the main disadvantages of HIMs are limited availability and high cost. Additionally, the limited amount of helium ions that can be adsorbed on the sample surface may not be suitable for large-scale sample manipulation.

=====Development direction of SEM=====
SEM already has high image quality and resolution, and more precise and faster imaging technology needs to be developed. This requires technologies such as higher accelerating voltages, new detector technologies, and more advanced software.
First, there is a way to further increase the resolution of the SEM by applying a higher accelerating voltage. In general, the higher the accelerating voltage, the higher the resolution of the SEM. Therefore, the resolution of the SEM can be increased by applying a higher accelerating voltage. However, applying a high voltage can damage the sample, so a new technique is needed to overcome this.
Second, the introduction of new detector technologies will also play a major role in the advancement of SEM. Brightness detectors, diffraction detectors, etc. currently used in SEM already provide very high image quality, but more advanced detector technology is needed for more precise imaging.
For example, as photoelectronic detectors used in SEMs or detectors for scanning electron microscopes develop, more precise imaging will become possible.
Third, the imaging speed and accuracy of the SEM can be increased by utilizing more advanced software techniques. Currently, a variety of software for imaging has been developed in SEM, and it will be possible to improve the imaging speed and accuracy of SEM by further developing it.
The direction of development of SEM like this will provide a wider range of applications in various fields such as nano science, material science, and life science, while making progress in more precise and faster analysis and processing technology.

 

=====Overview=====
The field of electron microscopy plays a very important role in materials and biological research.
Various equipment such as SEM, TEM, EDS, and STEM have been developed and used in various fields according to their principles and characteristics. Although these instruments are very useful for research, there are limitations in sample handling and management.
Expert knowledge and technical skills are required to overcome these limitations. Therefore, continuous learning and research are required in the field of electron microscopy. Microscopy techniques such as SEM, TEM, and FIB in the field of science and technology play a large role in the development of modern science. These microscopy technologies play an important role in the field of material research and analysis, and are used in various fields such as materials science, nanoscience, and life science. In particular, SEM can analyze the shape, surface structure, and chemical composition of most solid materials, so it is used in various fields such as material research, nanoscience, and environmental science. TEM is effectively used to confirm the detailed structure inside a material, and is widely used in life science, nanoscience, and materials research.
FIB is used in various fields such as nano-processing, nano-analysis, and materials research. In the future, these microscopy technologies will be further utilized in various fields such as nanoscience, material science, and life science, as more precise and faster analysis and processing technologies are developed. In particular, with the development of nanotechnology, it is expected to play an important role in analyzing the structure and properties of nanomaterials.
In addition, it is expected that microscope technologies such as SEM, TEM, and FIB will play a major role in the development of more precise material analysis, processing, and manufacturing technologies, while acquiring higher image quality and resolution through new analysis technologies and technology convergence. Microscopy techniques such as SEM also play an important role in the life sciences. By analyzing materials such as cells, tissues, and biofilms, it can be of great help in identifying functions and roles in vivo, diagnosing and treating diseases, and developing new drugs.
In addition, recently, research on extracting and analyzing information from microscopic images such as SEM through convergence with artificial intelligence is also being conducted. This enables faster and more accurate data analysis and prediction, and is expected to develop more advanced analysis technology through combination with artificial intelligence technology. Therefore, SEM and various microscopy technologies have a wide range of application potential in the field of science and technology, and in the future, more advanced technologies will be used in more diverse fields. In particular, combined with technologies such as artificial intelligence and machine learning, the possibility of application to automatic analysis and pattern recognition of SEM images, sample classification and feature prediction is also increasing. These developments are of high value not only in science and technology, but also in industry.
For example, it has high potential for application in defect analysis in the semiconductor manufacturing process, manufacturing and characterization of nanomaterials, and cell and tissue observation in the field of life science. Microscopy technology is also expected to play a large role in the medical field. Microscopic techniques such as SEM and TEM can provide important information for diagnosis and treatment of diseases by observing cell structures and pathological changes. In addition, the possibility of using nanoparticles in the field of drug delivery and tissue engineering is increasing.
Finally, SEM and various microscopy techniques also play an important role in education. Through SEM educational models used in science education, you can stimulate students' scientific curiosity and provide them with opportunities to visually observe and learn various phenomena. Therefore, SEM and various microscopy technologies are expected to play an important role in various fields such as science, technology, industry, environment, medicine, and education, both now and in the future.

[Appendix]
====Coating=====
Au (Aurum) coatings and Platinum (Pt) coatings are two of the most commonly used coating materials in the SEM specimen fabrication process. First, the Au coating is less expensive than the Pt coating and has a lower evaporation temperature, so less heat is applied to the sample and the electrical conductivity of the sample surface can be increased. However, it is difficult to form a consistent coating thickness on the surface of Au, and the brightness of the sample may decrease after coating. Also, the Au coating often does not affect the corrosion of the sample. On the other hand, the Pt coating is relatively more expensive than the Au coating, but the coating thickness is more uniform and the brightness of the sample is more maintained. In addition, Pt has high electrical conductivity, which can increase the resolution of SEM imaging. However, the brightness of the Pt sample may decrease depending on sample corrosion or coating thickness.
Therefore, the choice between Au and Pt coatings may depend on the characteristics of the sample and the purpose of the SEM analysis. In addition to Au or Pt coatings, other coating methods for preparing SEM samples include carbon coating and measuring samples directly in SEM without coating. First, carbon coating is used for SEM analysis by depositing a thin carbon layer on the sample surface. This method is widely used because it is relatively simple and can be applied at low cost.
However, the thickness of the carbon layer can be irregular, and the carbon layer can combine with surface impurities, distorting the analysis results. In addition, the method of measuring samples directly on the SEM without coating is used for samples with smooth surfaces. Although this method can save sample handling and time, it is not applicable for materials requiring high electron density in SEM. Here's a quick summary of the pros and cons:

-Au coating: Provides high contrast for SEM imaging, the coating layer is relatively uniform, and the measurement results are less variable. However, it is expensive, and sometimes the electron beam cannot reach the surface because the Au layer is very thin.
-Pt coating: It has high efficiency for electron generation required for SEM analysis and can be applied at a relatively low cost. However, the Pt coating layer can be much more inhomogeneous than the Au coating, which can affect the SEM image depending on the coating thickness.
-Carbon coating: inexpensive, simple, and suitable for use in SEM imaging. However, the carbon layer can form irregularly and combine with surface impurities to distort the analysis results.
-SEM analysis without coating: SEM analysis can be performed quickly and easily. However, it is only used on the smooth surface of the sample. Finally, there is also a metal coating method for electron beams using commercially available metals for electron beams. This method has a thicker coated layer than a carbon coating and can produce a more defined image. However, this method is relatively expensive and can have sample distortion issues. Besides Au or Pt, there are various coating methods for coating SEM samples. Typical coating methods include carbon coating, Cr coating, Cu coating, and Au-Pd alloy coating.
Carbon coating is a method of coating the surface of an SEM sample with special carbon pellets, which is effective in improving the resolution of SEM images due to its highly electron accepting properties. Carbon coatings are popular because they are relatively inexpensive and can be processed quickly.
Cr coatings are usually used on electrically shielded samples in SEMs and are effective in adding shading to SEM images to better reveal sample details. However, there are environmental issues that chromium can generate during the coating process.
Cu coatings are highly electronically conductive, making them suitable for SEM analysis. However, copper vapors generated during the coating process can be toxic. The Au-Pd alloy coating has performance similar to that of Au or Pt, and can make the surface of the sample smooth. However, it is not used much because of its high price.
Each coating method has advantages and disadvantages, and the most suitable coating method should be selected according to the characteristics of the SEM sample used.
Another coating method is carbon coating. Carbon coating is a method of coating the sample surface using carbon atoms. This method is cheaper than Au or Pt coating, and it can coat the sample surface very thinly and uniformly. The carbon coating also helps to charge the electron poles, which has the effect of improving the picture quality of the SEM. However, the disadvantage of carbon coating is that in the case of a sample with a smooth surface, the coating may break or adhere to the sample surface, distorting the shape of the sample. Carbon coatings can also be difficult to apply on some samples. Another coating method is ion beam coating. This method is a method of coating the surface of a sample using an ion beam.
This method can form a high-ensity coating layer to protect the sample surface. In addition, various types of coating materials are available, allowing you to select an appropriate coating method according to your sample. However, the disadvantage of ion beam coating is that heat is generated on the sample surface during the coating process, which can damage the sample, and the coating process can take a long time. Additionally, the relatively high cost of ion beam coating equipment often results in high coating costs.

 

=====Reference site=====

-Microscopy Society of America (MSA) (https://www.microscopy.org/) The MSA, the Society for Electron Microscopy, promotes research and education in electron microscopy and related fields, and shares related information and technologies. does. This site provides the latest information and research achievements in the field of electron microscopy, as well as information on related technologies and equipment.

 

-European Microscopy Society (EMS) (https://www.eurmicsoc.org/) EMS, the European Electron Microscopy Society, promotes electron microscopy research and education in Europe and carries out activities such as sharing related information and technologies. do. This site provides the latest information and research achievements in the field of electron microscopy, as well as information on related technologies and equipment.

 

-Microscopy and Analysis (https://www.microscopyanalysis.com/) Microscopy and Analysis is a website that provides a variety of information on electron microscopes and related fields, technologies, and equipment. The site provides the latest technology trends, research findings, product information, and more, as well as online technology workshops and webinars.

 

-Journal of Microscopy (https://onlinelibrary.wiley.com/journal/13652822) The Journal of Microscopy is an international journal that publishes research results on various fields of microscopy, including electron microscopy, optical microscopy, and atomic force microscopy. This site provides not only the latest research results, but also review articles on various topics in the field of electron microscopy and microscopy.

 

-Microscopy Today (https://www.microscopy-today.com/) Microscopy Today is a monthly academic journal in North America covering the latest information, research results, equipment and technology in the field of electron microscopy and microscopy. The site provides the latest technology trends, product information, information on academic events, and hosts technical workshops and webinars.

 

-The Korean Society of Electron Microscopy (http://www.kjems.or.kr/) The Korean Society of Electron Microscopy is an academic society created to promote academic and technological development in the field of electron microscopy and to exchange and share information among researchers. It publishes the ‘Journal of the Korean Society of Electron Microscopy’, an academic journal, and you can interact with researchers in the field of electron microscopy and learn the latest trends.

 

-The Korean Society of Microscopy (http://ksmst.or.kr/) The Korean Society of Microscopy is an academic society that supports academic presentations and exchanges related to microscopy for researchers and students in the field of optical microscopy and electron microscopy. It publishes the ‘Journal of the Korean Society of Microscopy’, an academic journal, and provides information on microscope-related technologies, theories, and applications.

 

-SEMTech Solutions (https://www.semtechsolutions.com/) SEMTech Solutions is an American company providing solutions for electron microscopes and related technologies. It provides information on products and services, and you can find out the scope and limitations of SEM and EDS, as well as their strengths and weaknesses.

 

-Microscopy Society of America (https://www.microscopy.org/) The Microscopy Society of America is a society that exchanges and shares information with researchers in the field of microscopy around the world. We publish academic journals and academic journals, and you can obtain information on microscope-related technologies and applications.

 

-The Royal Microscopical Society (https://www.rms.org.uk/) The Royal Microscopical Society is a society for researchers in the field of microscopy in the UK. We publish academic journals and academic journals, and you can obtain information on microscope-related technologies and applications.

 

=====Terms=====

-Secondary electrons: New electrons created as the electron beam interacts with the surface, and has a different energy than the previous electron.

 

-Backscattered electrons: As electrons bounce back as the electron beam interacts with the surface, the degree of electron reflection varies depending on the element or density of the surface.

 

-X-ray characteristic peak: This is the frequency of X-rays emitted as electrons move from a specific element, and each element has a unique frequency.

 

-Energy resolution: As the frequency resolution of X-rays measured by EDS, it refers to the ability to distinguish between high-energy X-rays and low-energy X-rays.

 

-Scanning area: This is the area observed by moving the electron beam in SEM. The size of this area affects the resolution of SEM analysis.

 

-Working distance: This is the distance between the electron beam and the sample in SEM. If this distance is short, the analysis target may be damaged, and if this distance is long, the resolution will be low.

 

-Spectrum - It refers to the graph representation of the data obtained as a result of EDS analysis. In general, the X-axis represents the energy value of an X-ray, and the Y-axis represents the number of detections of each X-ray.

 

-Peak - Refers to the part where each X-ray appears on the spectrum. Peaks are represented by the size and shape of X-ray energy and the number detected. -Background - Refers to the part other than the peak on the spectrum. This is usually the case when X-rays are not detected.

 

-Counts - The number of data points collected by the EDS analyzer on one peak.

-Dead time - The delay time that occurs when the EDS analyzer detects high-energy X-rays. This prevents the detection of low-energy X-rays and causes distortion of the analysis results.

 

-ZAF correction - Correction method for X-ray detection in EDS analysis. Z is the elemental composition of the object, A is the absorption of each element, and F is the calibration constant representing the interaction of protons and electrons inside the object.

 

-K-alpha line - One of the types of X-ray emission, referring to the X-rays emitted when a K-shell electron falls into an L-shell. Generally, it has the highest energy and has the most peaks.

-M-line - One of the types of X-ray emission, referring to X-rays emitted when an M-shell electron falls into another shell. Lower energy than K-alpha rays.

 

-Escape peak - A phenomenon in which X-rays are not absorbed by the target and are measured below the peak. It usually has 2/3 the energy of X-rays.

 

-SIMS (Secondary Ion Mass Spectrometry): Releases ions from the sample surface and analyzes the distribution of elements inside the sample using ion mass spectrometry.

 

-Backscattered Electron (BSE): In SEM, an electron beam collides with a sample and bounces back. Since the degree of reflection of BSE varies depending on the atomic number and mass of the sample, the distribution of elements can be identified using the color difference in the SEM image.

 

-X-ray: One of the electron beams measured in EDS. It is a beam emitted by the movement of atoms in the sample as the electron beam collides with the sample. Since each element has a unique X-ray spectrum, it can be used to determine the presence and amount of the element in the sample.

 

-Energy resolution: This is an index that indicates the energy resolution of X-rays measured by EDS. The smaller the difference between the measured X-ray energy and the actual X-ray energy, the higher the energy resolution.

 

-Count Rate: This refers to the total number of X-ray signals collected from the X-ray detector in SEM-EDS. A higher Count Rate means a higher rate of analysis.

 

-Electron gun: As a source for generating electrons in SEM, it is a part shaped like a bullet.

 

-Cathode: A cathode that emits electrons from an electron gun.

 

-Anode: Anode for accelerating electrons in Electron gun.

 

-Beam current: A value representing the intensity or amount of electron beams when the SEM scans the sample surface.

 

-Beam voltage: A value representing the voltage applied to the electron beam in the SEM.

 

-Backscattered electron (BSE): In SEM, a beam of electrons interacts with the sample surface to collect and analyze electrons bounced off the sample.

 

-Scintillator: An optical component for detecting electrons emitted from a sample in SEM.

 

-Photomultiplier: A component that detects and amplifies the light emitted from the scintillator in the SEM and converts it into an electronic signal.

 

-Accelerating voltage: This is the voltage to accelerate electrons in EDS.

 

-Detector: A part that detects X-rays in EDS.

 

-Energy resolution: A value representing the ability of EDS to accurately measure the energy of X-rays.