一般財団法人材料科学技術振興財団　MST List of Products and Services

In the mass production of LCD panels, it is necessary to remove defects (foreign substances and dirt). Therefore, investigating the causes of these foreign substances and dirt is effective for improving yield. Here, we introduce a case study evaluating foreign substances and dirt on LCD panels. TOF-SIMS can capture cleaning residues in the order of micrometers to centimeters as images. Additionally, by comparing with standard spectra, it is possible to estimate the components.

By conducting sample pretreatment, transportation, and measurement under a high-purity inert gas atmosphere, it is possible to evaluate while suppressing surface oxidation and moisture adsorption. ■Examples of Application - Semiconductor electrode materials Evaluation of peeling surfaces can be conducted while minimizing the effects of secondary contamination and oxidation. - Organic EL materials Working in an inert gas atmosphere from the moment of opening prevents material degradation. - Battery materials such as Li If processing in a N2 atmosphere is not possible for materials like Li, treatment can be performed in an Ar atmosphere as an alternative.

We will introduce a case where the permeability of water (H2O) in a thin film with a thickness of less than 1 µm was evaluated by measuring the distribution of deuterium (D) in the film. When hydrogen (H) is originally present in the thin film, it is difficult to distinguish whether the hydrogen is due to the influence of water. Therefore, treatment with heavy water (D2O) was performed, and the distribution of the naturally occurring isotope deuterium was measured in the depth direction using SIMS. By examining the depth distribution of deuterium, it is possible to estimate how deep the water has penetrated.

When analyzing and identifying unknown samples such as foreign substances, it is effective to analyze the data comprehensively from multiple measurement methods. We will introduce a case where FT-IR analysis, which is a vibrational spectroscopy method, was combined with XRF analysis, an elemental analysis method in the atmosphere, to identify two types of white powders.

This paper presents a case study analyzing the degradation components of organic materials that deteriorate due to atmospheric exposure, using GCIB (Ar cluster). The experiment utilized the organic EL material, Rubrene. Measurements of the atmosphere-exposed samples using TOF-SIMS revealed the presence of a mass (m/z 564) estimated to be Rubrene peroxide, as well as low molecular weight benzene-related masses (m/z 77, 105). It was confirmed that these degradation-related components exist at depths of approximately 1μm or more from the surface. *GCIB: Gas Cluster Ion Beam

In SIMS analysis of layered structure samples, there is a concern that in structures where the layer of interest is located at a deep position from the sample surface, the depth resolution may degrade due to the influence of the concentration distribution of the upper layers. In such cases, it is effective to remove the upper layers through pretreatment before analysis. This document presents an example of selectively and progressively removing layers from InP/InGaAs-based SHBT (Single Heterojunction Bipolar Transistor) samples.

Organic EL displays are advancing in practical applications by leveraging advantages such as high brightness, high-resolution color, and thinness due to their self-emissive principle. Organic EL devices are manufactured by stacking organic films, but analyzing the organic films in their stacked state has been challenging. This time, by using the XRR method, it has become possible to measure the film thickness and density of the organic films while maintaining the stacked state. Analysis of the thickness and density of stacked films is possible regardless of whether they are crystalline or amorphous.

Organic EL has advantages such as high brightness, high-resolution color, and thinness due to its self-emission principle, and it is expected to be one of the next-generation devices. Accurate analysis and evaluation of materials are crucial for improving characteristics, extending lifespan, and enhancing reliability; however, caution is required in handling them due to the use of highly reactive materials. A comparison between samples exposed to the atmosphere and those handled under a high-purity argon atmosphere confirms that oxidation (such as molecular ions +O, +OH, etc.) observed in atmospheric exposure is suppressed when handled in a high-purity argon environment.

We physically peeled off the buffer layer/Alq3 interface and conducted XPS analysis on the peeled surface (buffer layer side). By peeling in an inert gas atmosphere, we were able to expose the interface without destroying the chemical structure, and by transporting it to the XPS device while maintaining the inert gas atmosphere, we minimized post-peeling alterations (such as oxidation and moisture absorption). The main component of the buffer layer is LiF, and it was suggested that some of it may have oxidized. By controlling the atmosphere, it is possible to evaluate the oxidation states of metal elements such as Al and Li due to differences in film formation methods, treatment methods, and organic layers.

As a result of performing pre-treatment to depth direction analysis without exposing the organic layer of the degraded brightness element to the atmosphere, diffusion was observed at the Alq3/emission layer interface in the samples after applying voltage. Similar results were obtained from both Slope Mapping (Figure 1) and depth direction analysis using ion sputtering (Figure 2).

We investigated the distribution of the blue pigment "Cu phthalocyanine" dispersed on the polyethylene surface. TOF-SIMS analysis allows us to capture the distribution of organic materials with a pigment size of 1μm.

To extend the lifespan of organic EL devices, it is essential to evaluate the degradation caused by electromigration, making it important to investigate the diffusion state of electrode metal components into the organic layer. However, whether analyzed directly from the cathode side or through the SSDP method from the anode side, the depth resolution decreases, making it difficult to assess the diffusion from the interface into the organic layer. (Note: SSDP method refers to analysis from the backside. For details on the analytical method, see section B0013.) Therefore, by using special processing to expose the cathode/organic layer interface and the organic layer/anode interface, it has become possible to evaluate the organic layer with high depth resolution.

This shows the results of extracting the qualitative spectra of each layer by performing cutting processing of organic EL devices under controlled atmosphere. By conducting the cutting process of the organic EL devices under atmosphere control, we were able to obtain spectra of each layer that are closer to the true state.

Organic EL devices are prone to degradation in the atmosphere, so processing under an N2 atmosphere is necessary. We present the measurement results of Alq3 for organic EL devices that were machined in an N2 atmosphere and left in the atmosphere for 30 minutes, compared to those that were not exposed to the atmosphere. When left in the atmosphere, there is a strong tendency for peaks associated with oxygen to appear in Alq3. In the N2 atmosphere, there is a strong tendency for the parent ions of Alq3 to be observed. By avoiding exposure to the atmosphere, results closer to the true state can be obtained.

It is known that organic EL materials undergo changes when exposed to air. We present results obtained from TOF-SIMS regarding the surface state of luminescent materials left in a nitrogen atmosphere and in the atmosphere. In samples produced in a nitrogen atmosphere, parent ions are primarily detected, but when left in air, fragments with oxygen attached to the parent ions are detected. For materials that are prone to degradation, it is necessary to analyze them without exposing them to the atmosphere.

A comparison was made between commercially available digital audio players equipped with organic EL, one that had undergone electrical power and experienced brightness degradation and one that had not. As a result, no differences were observed in the TOF-SIMS spectra between the samples.

An example is shown where secondary ion mass spectrometry (SIMS) was used to analyze the intersection (4μm×10μm) of the data signal wiring and gate electrode wiring of a commercially available TFT LCD from the substrate side (SSDP-SIMS). By measuring from the substrate side (SSDP-SIMS), it becomes possible to provide data free from the influence of high-concentration layers or metal films on the surface side.

Organic EL is expected to be a self-emitting, flexible next-generation display and lighting panel, but further improvements in reliability are desired. By combining various methods, comprehensive evaluations such as structural analysis, condition analysis, and identification of degradation causes can be achieved.

For membranes with low density, it is difficult to achieve contrast at high acceleration voltages (hundreds of kV) due to the high transmission capability of the electron beam. However, in low acceleration voltage SEM-STEM images, slight differences in density can be reflected, allowing for clear composition contrast. This can be applied to organic EL films, low-k films, gate oxide films, TEOS films, BPSG films, etc., where the differences in density, average mass, and composition are small. 1) STEM observation using SEM equipment with lower acceleration voltage compared to dedicated TEM equipment. Measurement methods: TEM, SEM Product fields: LSI, memory, display, solar cells, lighting Analysis purposes: Shape evaluation, film thickness evaluation For more details, please download the materials or contact us.

It is possible to directly extract small pieces from the sample (micro-sampling) and perform FIB processing.

The transparent oxide semiconductor IGZO thin film is being researched and developed as a TFT material for displays. IGZO is a material whose properties change significantly based on the composition of the film, the presence of oxygen vacancies, and crystallinity, making it important to consider the correlation with film quality. We will introduce a case where the crystallinity, film thickness, and film density of three types of IGZO thin films with different heating temperatures were measured and compared using XRD and XRR. It was confirmed non-destructively that crystallization progresses at high temperatures, resulting in higher film density.

Pyrolysis GC/MS is a gas chromatography-mass spectrometer equipped with a pyrolysis device in the sample introduction section. For polymer materials that previously required complex pretreatment, samples can now be introduced into the GC for analysis without pretreatment by heating and decomposing them with the pyrolysis device. Additionally, by varying the temperature conditions of the pyrolysis device and the sampling conditions (double-shot method), it is possible to obtain two different types of information, such as additives and polymer materials, separately from the same sample, making the analysis of unknown polymer materials easier.

We conducted qualitative analysis of the components by measuring the surface under controlled conditions, minimizing alterations due to processing, on a commercially available digital audio player equipped with an organic EL display.

Polyimide is a material that is used in various fields, including electronic components, due to its high heat resistance and excellent electrical insulation properties. Since surface modification can enhance adhesion to other materials, it is important to understand the state of the modified layer. In this study, TOF-SIMS measurements were conducted under sputtering conditions that minimize the degradation of organic components, allowing for the evaluation of polyimide components in the depth direction. Using GCIB (Ar cluster) for sputtering enables the measurement of the targeted organic components in the depth direction. *GCIB: Gas Cluster Ion Beam

GaN-based LEDs have become widely used for lighting applications. To enhance the light extraction efficiency, textured surfaces may be created; however, these textures can lead to a degradation in depth resolution during depth analysis. We will present cases where flattening processing was applied to textured surfaces to mitigate the degradation of depth resolution and evaluate the depth concentration distribution, as well as cases where analysis was conducted from the backside (substrate side).

We will introduce a case where the depth concentration distribution of dopant elements such as Mg and Si in GaN-based LED structures was evaluated using multiple analysis modes. By selecting the optimal analysis mode according to the purpose in SIMS analysis, more precise evaluations can be achieved, so please feel free to consult with us.

Using a two-stage heating method with thermal decomposition GC/MS, we analyzed the material of the sealing agent around the display of commercially available smartphones. By heating the sample at a low temperature (250°C) and measuring the gas components generated using GC/MS, we can detect residual monomers and low molecular weight additives (polymerization initiators, antioxidants). Subsequently, by heating at a high temperature (550°C), we can decompose the polymers and estimate their constituent components. This revealed that the sealing agent is made of a UV-curable material.

Regarding foreign substance analysis, it has traditionally been difficult to analyze using microscopic FT-IR analysis or Raman analysis due to the influence of the substrate. However, with the introduction of micro-sampling tools, it has become possible to reduce that influence. We will introduce examples of analysis for two types of foreign substances.

Copper (Cu), used as wiring material, forms an oxide film in the air. Here, we present a case study evaluating the differences in film thickness due to variations in storage environments. Copper (Cu) wrapped in aluminum foil and copper (Cu) stored in a plastic bag were each kept for 40 days, and the oxide film thickness was measured using TOF-SIMS. Additionally, a continuous investigation over approximately 20 days confirmed reproducibility. TOF-SIMS allows for depth profiling analysis of inorganic materials such as oxides and metals. Measurement method: TOF-SIMS Product fields: Displays, LSI, Memory, Electronic components Analysis purpose: Evaluation of chemical bonding states For more details, please download the materials or contact us.

The surface of copper (Cu) metal exposed to the atmosphere is covered with a natural oxide film, and it is known that such copper surfaces can be broadly classified into the states of "Cu," "Cu2O," "CuO," and "Cu(OH)2." By conducting depth profile analysis of commercially available standard powders of "Cu2O," "CuO," and "Cu(OH)2" using TOF-SIMS, it was found that it is possible to obtain characteristic molecular ions corresponding to each state. Using these molecular ions, it became possible to evaluate the depth profile of the natural oxide film on the surface of metallic Cu. Measurement method: TOF-SIMS. Product fields: Display, LSI, Memory, Electronic components. Analysis purpose: Evaluation of chemical bonding states. For more details, please download the materials or contact us.

- Photoluminescence measurement (PL measurement) can be conducted not only at room temperature but also by placing the sample in a cryostat for low-temperature measurements. Low-temperature measurements tend to show an increase in peak intensity and a decrease in peak full width at half maximum compared to room temperature measurements, which may provide insights into various energy levels. - Below, we will explain the precautions for low-temperature measurements and the differences in spectral shapes between room temperature and low-temperature measurements.

This text introduces an example of evaluating the composition and bonding states of GaN films used in LEDs and power devices using XPS. Understanding how the composition and bonding states change due to film formation conditions and surface treatments is effective for process management. It is important to appropriately select the X-rays used during the evaluation according to the purpose. Measurement conditions for each focus will also be presented.

In semiconductor devices, their performance is greatly influenced by the combination of work functions of various materials that make up the device. Therefore, attempts have been made to control the work function through surface treatments and modifications, and it is important to verify their effects. This document presents an example of evaluating the change in work function of ITO (Sn-doped In2O3), used as an electrode material in organic ELs and solar cells, before and after surface plasma treatment using UPS analysis.

In XPS analysis, the binding state evaluation of the material surface is conducted by observing the energy of photoelectrons obtained through X-ray irradiation. It allows for the assessment of whether metal elements are in an oxidized state, and for elements with significant energy shifts (chemical shifts) due to oxidation, it also enables the evaluation of the presence and proportion of multiple valences. Below are the main metal elements and oxides for which multiple valence evaluations are possible.

Self-assembled monolayers (SAMs), which are oriented organic films, have their functions and properties, such as surface wettability and adsorption, altered by orientation and orientation angle. Using XAFS with synchrotron radiation, it is possible to evaluate the orientation and orientation angle of organic film materials by analyzing the X-ray incidence angle dependence of peak intensity.

The electron diffraction method using an electron microscope is classified into three types based on the way the electron beam is incident on the sample. The characteristics of each type and examples of data are presented. It is necessary to choose the appropriate method according to the size of the evaluation object and the analysis purpose.

Organic EL (OLED) is used in various applications such as high-definition display panels and lighting, and the demand for layer structure analysis and degradation analysis is increasing. However, since it is formed by combining various organic materials, elemental analysis alone can only capture some phenomena. This document presents a case study where depth direction analysis data of OLED was obtained using TOF-SIMS and analyzed through MSDM (Mass Spectra Depth Mapping).

In depth profiling analysis using TOF-SIMS, if the positional information on the plane (x, y) is ignored, mass spectra exist at each depth (z), resulting in three-dimensional data of depth, mass, and spectral intensity. The visualization of this three-dimensional data as a single image is called MSDM (Mass Spectra Depth Mapping) representation.

Organic EL (OLED) is used in various applications such as high-definition display panels and lighting, and the demand for layer structure analysis and degradation analysis is increasing. However, since it is formed by combining various organic materials, elemental analysis alone can only capture a portion of the phenomena. This document presents a case study where depth direction analysis data of OLED was obtained using TOF-SIMS, and insights into the degradation of the sample were gained through MSDM (Mass Spectra Depth Mapping).

Silicon oxide films are widely used as gate dielectrics in MOS devices and as anode materials in lithium-ion secondary batteries, but it is known that the presence of intermediate oxides and the bonding states at the interface have a significant impact on device characteristics. XAFS measurements using synchrotron radiation can detect information from a depth of several tens of nanometers from the sample surface, allowing for non-destructive analysis of the structure and bonding states in both bulk and at the interface. This document presents a case study investigating the presence of intermediate oxides in silicon oxide films using XAFS.

Organic EL displays are materials that hold the potential for high resolution and low power consumption, and market expansion is expected. In recent years, there has been a trend towards miniaturizing pixel arrangements to achieve higher image quality. When measuring small pixels, conventional oblique cutting TOF-SIMS measurements made it difficult to evaluate in the depth direction. However, by introducing GCIB (Ar cluster), it has become possible to evaluate organic EL materials in the depth direction with good reproducibility, even for small pixels, and to assess material degradation and diffusion as well. *GCIB: Gas Cluster Ion Beam

The temperature-programmed desorption gas analysis method (TDS) is a mass spectrometry technique that directly heats a sample by irradiating it with infrared light and monitors the gases generated at each temperature. When analyzing samples that cannot absorb infrared light, such as glass substrates, it is possible to conduct the analysis by changing the sample stage from transparent to black. The black stage absorbs infrared light, raising its temperature, which in turn increases the temperature of the sample through thermal conduction, generating gases.

Epoxy resin is excellent in heat resistance, chemical resistance, and insulation properties, and also has high mechanical strength, making it suitable for various applications such as insulation materials for electronic devices, adhesives, paints, and construction materials. However, due to the lack of solvent solubility, the analytical methods for structural determination are limited. This case presents an example of thermal decomposition GC/MS measurement of epoxy resin used as a sealing material for LEDs. The thermal decomposition products reflecting the structures of the main agent and curing agent were obtained, and this resin was estimated to be a bisphenol A/anhydride type epoxy resin.

TDS is a method that heats samples in a vacuum environment and monitors the gases that are released. When measuring organic substances, it can be difficult to obtain accurate measurements due to contamination of the equipment from large amounts of gas release. However, by adjusting the sample amount and analysis conditions in advance to control the amount of gas released, analysis becomes possible. Below are the results of TDS analysis conducted on organic films. We were able to capture the phenomenon where surface-adsorbed water is released at low temperatures, and the intensity of gas release increases with rising temperature.

We will introduce a case where the permeability of water (H2O) in glass materials was evaluated by measuring the distribution of deuterium (D). When hydrogen (H) is already present, it is difficult to distinguish whether the hydrogen is due to the influence of water. Therefore, treatment with heavy water (D2O) was performed, and the distribution of the stable isotope deuterium was measured in depth using SIMS. By examining the depth distribution of deuterium, it is possible to estimate how deep the water has penetrated.