Applications

Creating a perfect image requires a combination of theoretical knowledge and practical experience and a balance between many factors. This process may encounter some challenging issues in the use of  Electron Microscope.    Astigmatism   Astigmatism is one of the most difficult corrections to make in an image and requires practice. The middle image in the following figure is a correctly focused image after astigmatism correction. The left and right images are examples of poor astigmatism correction, resulting in stretched stripes in the image.   To achieve precise imaging, the cross-section of the Electron Beam (probe) should be circular when it reaches the specimen. The cross-section of the probe may become distorted, forming an elliptical shape. This can be caused by a series of factors such as machining accuracy and defects in the magnetic pole piece or copper winding in the casting of the ferromagnetic coil. This deformation is called vignetting and can result in difficulties in focusing.   Severe astigmatism is one of the most difficult corrections to make in an image and requires practice. The middle image in the following figure is a correctly focused image after astigmatism correction. The left and right images are examples of poor astigmatism correction, resulting in stretched stripes in the image. can manifest as "stripes" in the X direction in the image. As the image transitions from under-focus to over-focus, the stripes will change to the Y direction. When the focus is precise, the stripes disappear, and proper focusing can be achieved if the spot size is appropriate.   When magnified around 10,000 times, if there are no stripes in either direction when the objective is adjusted to under-focus or over-focus, it is generally considered that there is no astigmatism in the image. Astigmatism is usually negligible in images below 1000 times magnification.   The best approach to correct vignetting is to set the X and Y vignetter offsets to zero (i.e., no astigmatism correction) and then focus the specimen as finely as possible. Then adjust the X or Y astigmatism control (cannot be adjusted simultaneously) to obtain the best image and refocus.   Edge Effects   Edge effects occur due to enhanced Electron Emission at the edges of the specimen. The edge effects are caused by the influence of morphology on the generation of secondary electrons and are also the reason for the image contour produced by the secondary electron detector. Electrons preferentially flow towards the edges and peaks and emit from the edges and peaks, resulting in lower signal intensity in areas obstructed by the detector, such as recesses. Backscattered electrons emitted from the region of the sample facing the detector also enhance the topographic contrast. Reducing the accelerating voltage can reduce edge effects.   Charging Effects   Uncontrolled discharge of electrons that accu...

Focused Ion Beam (FIB) is a microfabrication instrument that utilizes an electron lens to focus an ion beam into a very small size for precision cutting.   Working Principle   Liquid Metal Ion Source The ion source is the heart of the FIB system, and the accurate focusing of the ion beam begins with the emergence of liquid metal ion sources. The ions generated by liquid metal ion sources, mostly utilizing gallium (Ga) as the metal material, have high brightness and petite source sizes. Liquid metal ion sources are formed by the field-induced ion emission from a liquid metal surface under a strong electric field.   In the manufacturing process of the source, a tungsten wire with a diameter of about 0.5 mm is electrochemically etched to create a tungsten needle with a tip diameter of only 5-10 μm. The molten liquid metal is then adhered to the tip of the tungsten needle. Under the application of a strong electric field, the liquid metal forms a tiny tip (Taylor cone) due to the electric field force, with an electric field intensity of up to 10^10 V/m. Under such a high electric field, metal ions on the liquid surface evaporate into an ion beam through field evaporation. Despite the low ion current of only a few microamperes, the current density can reach approximately 106 A/cm2, and the brightness is about 20 μA/sr.   Focused Ion Beam System Focused ion beam technology utilizes electrostatic lenses to focus the ion beam into a very small size for microfabrication. Commercial FIB systems typically extract the particle beam from liquid metal ion sources. Gallium (Ga) is often used as a metal material due to its low melting point, low vapor pressure, and good oxidation resistance.   By applying an external electric field (Suppressor) to the top of the ion column, a small tip of the liquid metal or alloy can be formed. With the negative electric field (Extractor) applied, the tip of the metal or alloy is pulled out to generate the ion beam. The ion beam is then focused using electrostatic lenses, and the size of the ion beam can be controlled by an Automatic Variable Aperture (AVA) with an adjustable aperture. The desired ion species are selected using an E×B mass analyzer. Finally, the ion beam is focused on the specimen and scanned using an octupole deflector and an objective lens. The ion beam bombards the specimen, and the secondary electrons and ions generated are collected, imaged, or used for physical sputtering, cutting, or grinding.   Basic Functions   The basic functions of a focused ion beam microscope can be divided into four categories:   1. Precisional Cutting: Achieving cutting through the physical collision of ions. Widely used in Cross-Section processing and analysis of Integrated Circuits (ICs) and LCDs.   2. Selective Deposition: Decomposing organic metal vapor or gas-phase insulating material with the energy of the ion beam to locally deposit conductive or non-conductive ...

Based on the Dual-beam Electron Microscope DB550 independently controlled by CIQTEK, the Transmission Electron Microscope (TEM) nanoscale sample preparation of 28nm process node chips was successfully achieved. TEM verification can clearly analyze the key dimensions of each structure, providing a domestic precision detection solution for semiconductor process defect analysis and yield improvement.  

Metal materials play an indispensable role in modern industry, and their performance directly affects product quality and service life. With the continuous development of materials science, higher requirements have been put forward for the microscopic structure and composition analysis of metal materials. As an advanced characterization tool, Scanning Electron Microscope (SEM) can provide high-resolution surface morphology information and combine with spectroscopic analysis techniques for elemental composition determination, making it an important tool in metal material research. This article aims to discuss the application of SEM technology in the characterization of metal materials and provide references and guidance for related research.   Basic Principles of Scanning Electron Microscope (SEM) The working principle of a scanning electron microscope is based on the interaction between an electron beam and the sample surface. When a high-energy electron beam scans the sample surface, various signals are generated, including secondary electrons, backscattered electrons, characteristic X-rays, etc. These signals are collected by corresponding detectors and processed to form surface morphology images or elemental distribution maps of the sample.   SEM Sample Preparation for Metal Materials   Microstructural Analysis: CIQTEK SEM provides high-resolution images to help researchers observe and analyze the microstructure of metals and composite materials, such as grain size, shape, phase distribution, and defects (e.g., cracks, and inclusions). This is crucial for understanding the relationship between material properties and processing techniques.   α ＋ β Titanium Alloy The heat-affected zone is the most vulnerable area in a welded joint. Studying the changes in the microstructure and properties of the welded area are of great significance for solving welding issues and improving welding quality.   Composition Analysis: Equipped with an EDS or a WDS system, CIQTEK SEM allows for qualitative and quantitative elemental composition analysis. This is highly important for studying the distribution patterns of alloying elements and their impact on material properties.   Elemental Line Analysis by EDS By combining SEM with EDS analysis, the compositional changes and    element distribution of impurities in the welding area can be observed.   Failure Analysis: After failures such as fractures, corrosion, or other forms of damage occur in metals and composite materials, CIQTEK SEM is a key tool for analyzing mechanism failure. By examining fracture surfaces, corrosion products, etc., the root cause of the failure can be identified, providing insights for improving material reliability and lifespan.   2A12 Failure of aluminum alloy components 2A12 aluminum alloy exhibits various precipitation phases, which can be distinguished morphologically as        ...

Definition and Characteristics of Crystals: Crystals are materials formed by the regular and periodic arrangement of particles (molecules, atoms, ions) in three-dimensional space. Crystals can be classified into single crystals and polycrystals. The formation of crystals involves the process of particles arranging themselves in a regular pattern. The regular arrangement of particles gives rise to a structured framework inside the crystal, making crystals solids with a specific lattice structure. Crystals exhibit regular geometric shapes, have fixed melting points, and display anisotropic properties such as mechanical strength, thermal conductivity, and thermal expansion. Crystals are abundant in nature, and most solid materials found in nature are crystals. Gases, liquids, and amorphous materials can also transform into crystals under suitable conditions. X-ray diffraction is commonly used to identify whether a material is a crystal or not. Melting Point and Distribution of Crystals:  The regular arrangement of atoms in crystals contributes to their fixed melting and solidification points, which is a distinguishing feature of crystals compared to amorphous materials. Crystals are diverse in morphology in nature, ranging from common substances like salt and sugar, minerals that make up the Earth's crust, to metals and semiconductor materials. Electron Microscopes and EBSD techniques can help understand the stability of crystals under different conditions and provide scientific insights for material selection and applications.   Single Crystals and Polycrystals: A single crystal consists of a continuous crystal lattice where the atomic arrangement remains consistent throughout the crystal, resulting in the anisotropic properties of the crystal. Single crystals are ideal for certain applications, such as silicon single crystals used as the foundation material for integrated circuits in the semiconductor industry.   Polycrystals, on the other hand, are composed of multiple grains with different orientations. Although the individual grains possess the same crystal lattice, their orientations are random, resulting in a polycrystal without macroscopic anisotropy. However, under specific processing conditions, the grains in polycrystals can align preferentially along a specific direction, forming a preferred orientation, which is known as crystallographic texture. Crystallographic texture can enhance the properties of materials in specific directions. For example, control of texture in metal processing can improve the material's ductility or strength. Analytical laboratories, such as the GoldTest Lab, provide precise analysis and testing of single crystals and polycrystals, offering reliable insights for material applications.   Importance of Crystal Orientation:  The analysis of crystal orientation is crucial for understanding material properties. Crystal orientation describes the relative position of crystal axes in t...

Recently, a research paper titled "Phononic modulation of spin-lattice relaxation in molecular qubit frameworks" by the research team led by Dr. Sun Lei from the School of Science at Westlake University was published in Nature Communications.   Figure 1: Hydrogen bonding network and phonon modulation of spin-lattice relaxation in MQFs   The team used CIQTEK pulsed Electron Paramagnetic Resonance (EPR) Spectroscopy X-band EPR100 and W-band EPR-W900 to characterize two molecular qubit framework materials containing semi-quinone radicals.   Figure 2: Spin dynamic properties of MgHOTP and TiHOTP   They discovered that hydrogen bonding networks in these materials led to decreased structural rigidity, resulting in sub-terahertz optical phonons, reduced Debye temperature, increased acoustic phonon density of states, and promoted spin-lattice relaxation. Deuterium substitution in the hydrogen bonding network further lowered the optical phonon frequencies and shortened the spin-lattice relaxation time.   Figure 3: Vibrational spectra of MgHOTP and TiHOTP   Based on these findings, the researchers proposed a molecular qubit framework design to control phonon dispersion precisely, suppress spin-lattice relaxation, and improve qubit performance. This achievement provides new insights and opportunities for solid-state integration and quantum information applications of molecular electron spin qubits.     Figure 4: Spin lattice relaxation mechanism of MgHOTP and TiHOTP Figure 5: Influence of deuterium substitution in the hydrogen bonding network on low-frequency optical phonons and spin-lattice relaxation in MgOTP   In summary, this study revealed that the structural rigidity of molecular qubit framework materials can be used to control phonon dispersion, suppress spin-lattice relaxation, and improve quantum coherence and the applicable temperature range. The research findings can potentially advance the solid-state integration and molecular quantum information technology of molecular electron spin qubits.

What is the Recrystallization Process?   Recrystallization is an important phenomenon in materials science that involves the microstructural recovery of material after plastic deformation. This process is crucial for understanding material properties and optimizing processing techniques.   Mechanisms and Classification of Recrystallization   Recrystallization processes are typically triggered by heat treatment or thermal deformation and involve the natural recovery of materials after the generation of defects during deformation. Defects such as dislocations and grain boundaries promote the reduction of system-free energy at high temperatures through dislocation rearrangement and annihilation, leading to the formation of new grain structures. Recrystallization can be classified into static recrystallization (SRX) and dynamic recrystallization (DRX). SRX occurs during annealing processes, while DRX takes place during thermal deformation. Furthermore, recrystallization can be further subdivided based on specific mechanisms, such as continuous dynamic recrystallization (CDRX), discontinuous dynamic recrystallization (DDRX), geometric dynamic recrystallization (GDRX), and metadynamic recrystallization (MDRX). These classifications are not strictly defined, and researchers may have different interpretations.   Factors influencing recrystallization   The recrystallization process is influenced by various factors, including the stacking fault energy (γSFE), initial grain size, thermal processing conditions, and second-phase particles. The magnitude of the stacking fault energy determines the dislocation breakdown and mobility, thereby affecting the recrystallization rate. Smaller initial grain sizes and suitable thermal processing conditions, such as high temperature and low strain rates, facilitate recrystallization. Second-phase particles can significantly influence the recrystallization process by hindering grain boundary motion.   Application of imaging techniques   EBSD and TEM are two classic imaging techniques used in recrystallization studies. EBSD analyzes the distribution and percentage of recrystallized grains using the DefRex map, although resolution limitations may pose accuracy issues. TEM, on the other hand, provides a direct observation of material substructures, such as dislocations, offering a more intuitive perspective for recrystallization studies.   Application of EBSD in recrystallization studies   EBSD is used to determine whether grains have undergone recrystallization by observing grain boundaries. For example, in the DefRex maps of forged TNM alloys, grains surrounded by high-angle boundaries are typically considered recrystallized grains. This technique provides detailed information about grain orientations and grain boundary types, aiding in the understanding of microstructural changes during recrystallization.   BC+GB (grain boundary) map of forged TiAl alloy  ...

Transmission Electron Microscopes (TEM) and Scanning Electron Microscopes (SEM) are indispensable tools in modern scientific research. Compared to optical microscopes, electron microscopes offer higher resolution, allowing for the observation and study of specimens' microstructure at a smaller scale.   Electron microscopes can provide high-resolution and high-magnification images by utilizing the interactions between an electron beam and a specimen. This enables researchers to obtain critical information that may be difficult to obtain through other methods.   Which microscope is more suitable for you?   When choosing the appropriate electron microscopy technique for your needs, various factors need to be considered to determine the best fit. Here are some considerations that can help you make a decision:     Field Emission TEM | TH-F120 Analysis Purpose: First, it is important to determine your analysis purpose. Different electron microscopy techniques are suitable for different types of analysis. a. If you are interested in surface features of a specimen, such as roughness or contamination detection, a Scanning Electron Microscope (SEM) may be more suitable. b. However, a transmission electron microscope (TEM) may be more appropriate if you want to understand the crystal structure of a specimen or detect structural defects or impurities.   Resolution Requirements: Depending on your analysis requirements, you may have specific resolution needs. In this regard, TEM generally has a higher resolution capability compared to SEM. If you need to perform high-resolution imaging, especially for observing fine structures, TEM may be more suitable.   Specimen Preparation: An important consideration is the complexity of specimen preparation. a. SEM specimens typically require minimal or no preparation, and SEM allows for more flexibility in specimen size, as they can be directly mounted on the specimen stage for imaging. b. In contrast, the specimen preparation process for TEM is much more complex and requires experienced engineers to operate. TEM specimens must be extremely thin, typically below 150 nm, or even lower than 30 nm, and as flat as possible. This means that TEM specimen preparation may require more time and expertise.   Type of Images: SEM provides detailed three-dimensional images of the specimen surface, while TEM provides two-dimensional projection images of the internal structure of the specimen. a. Scanning Electron Microscope (SEM) provides three-dimensional images of the surface morphology of the specimen. It is mainly used for morphology analysis. If you need to examine the surface morphology of a material, SEM can be used, but you need to consider the resolution to see if it meets your experimental requirements. b. If you need to understand the internal crys...