Nitrogen-incorporated tetrahedral amorphous carbon (ta-C:N) has electrochemical properties that are comparable to boron-doped diamond (BDD), but can be deposited at low temperatures, and is scalable across substrate areas substantially exceeding what is currently possible for BDD. Most published studies of ta-C:N electrodes focus on films deposited on conductive substrates due to the relatively high resistivity of ta-C:N compared to other carbon and metal-based electrodes. However, some of the most compelling applications of electrochemistry, for example, optically transparent spectroelectrochemical devices, require insulating substrates such as fused silica glass (FSG) or polymers. In this study, we deposited 50 nm of ta-C:N by laser controlled pulsed cathodic vacuum arc (Laser-Arc) onto insulating FSG to investigate the electrochemical response compared to conductive silicon (c-Si) substrates. No oxidation or reduction of potassium ferrocyanide during cyclic voltammetry (CV) could be observed at the FSG electrode. To address this, we introduced a 5 nm chromium (Cr) interlayer deposited by magnetron sputtering between ta-C:N and FSG. This electrode configuration led to clear cathodic and anodic CV peaks of potassium ferro/ferricyanide but with an increased peak separation compared to the c-Si electrode. However, the peak separation could be reduced to values comparable to ta-C:N deposited on c-Si by optimizing Cr sputtering conditions and introducing an argon plasma pretreatment of the FSG surface. Atomic force microscopy revealed that these changes improved the Cr growth homogeneity, which in turn increased the electrical conductivity of the Cr interlayer as determined by 4-point probe measurements.
{"title":"Nitrogen-incorporated tetrahedral amorphous carbon optically transparent thin film electrode","authors":"Nina Baule, L. Haubold, T. Schuelke","doi":"10.1116/6.0003786","DOIUrl":"https://doi.org/10.1116/6.0003786","url":null,"abstract":"Nitrogen-incorporated tetrahedral amorphous carbon (ta-C:N) has electrochemical properties that are comparable to boron-doped diamond (BDD), but can be deposited at low temperatures, and is scalable across substrate areas substantially exceeding what is currently possible for BDD. Most published studies of ta-C:N electrodes focus on films deposited on conductive substrates due to the relatively high resistivity of ta-C:N compared to other carbon and metal-based electrodes. However, some of the most compelling applications of electrochemistry, for example, optically transparent spectroelectrochemical devices, require insulating substrates such as fused silica glass (FSG) or polymers. In this study, we deposited 50 nm of ta-C:N by laser controlled pulsed cathodic vacuum arc (Laser-Arc) onto insulating FSG to investigate the electrochemical response compared to conductive silicon (c-Si) substrates. No oxidation or reduction of potassium ferrocyanide during cyclic voltammetry (CV) could be observed at the FSG electrode. To address this, we introduced a 5 nm chromium (Cr) interlayer deposited by magnetron sputtering between ta-C:N and FSG. This electrode configuration led to clear cathodic and anodic CV peaks of potassium ferro/ferricyanide but with an increased peak separation compared to the c-Si electrode. However, the peak separation could be reduced to values comparable to ta-C:N deposited on c-Si by optimizing Cr sputtering conditions and introducing an argon plasma pretreatment of the FSG surface. Atomic force microscopy revealed that these changes improved the Cr growth homogeneity, which in turn increased the electrical conductivity of the Cr interlayer as determined by 4-point probe measurements.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141801491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ze-Xuan Liu, Xing-Yu Li, Quanzhi Zhang, J. Schulze, Ruobing Zhang, You-Nian Wang
Ion-beam etching (IBE) is widely used in the fabrication of high-quality blazed gratings due to its high resolution and directionality, which allows for the control of blazed angles and smooth surface profiles. Throughout the ion-beam etching process, the redeposition of sputtered species onto the wafer occurs, affecting the profile evolution and blazed angle. To investigate this phenomenon in the fabrication of blazed gratings, a self-consistent simulation model utilizing the cellular method has been developed to analyze the etching and redeposition mechanisms in the IBE process. The model yields good agreement with the experimentally observed evolution of the etching profile. By examining the density and velocity distributions of the sputtered species, the coexistence of etching and redeposition is confirmed and explained, highlighting the visually significant role of redeposition. Our model takes into account the “footing effect” that is unavoidable in mask manufacturing, and its impact on the morphology evolution during blazed grating IBE is studied.
{"title":"Impact of sputtering and redeposition on the morphological profile evolution during ion-beam etching of blazed gratings","authors":"Ze-Xuan Liu, Xing-Yu Li, Quanzhi Zhang, J. Schulze, Ruobing Zhang, You-Nian Wang","doi":"10.1116/6.0003745","DOIUrl":"https://doi.org/10.1116/6.0003745","url":null,"abstract":"Ion-beam etching (IBE) is widely used in the fabrication of high-quality blazed gratings due to its high resolution and directionality, which allows for the control of blazed angles and smooth surface profiles. Throughout the ion-beam etching process, the redeposition of sputtered species onto the wafer occurs, affecting the profile evolution and blazed angle. To investigate this phenomenon in the fabrication of blazed gratings, a self-consistent simulation model utilizing the cellular method has been developed to analyze the etching and redeposition mechanisms in the IBE process. The model yields good agreement with the experimentally observed evolution of the etching profile. By examining the density and velocity distributions of the sputtered species, the coexistence of etching and redeposition is confirmed and explained, highlighting the visually significant role of redeposition. Our model takes into account the “footing effect” that is unavoidable in mask manufacturing, and its impact on the morphology evolution during blazed grating IBE is studied.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Itsuki Misono, T. Motomura, T. Tabaru, Masato Uehara, Tetsuya Okuyama
Plasma discharge pulse length (tPLength) was investigated for its impact on the crystallinity of GaN films deposited on a sapphire substrate using a high-density convergent plasma sputtering device (CPSD). The study covered tPLength values from 1 to 200 ms, maintaining the substrate temperature at 200 °C. GaN films showed preferential orientation along the (0002) plane for all tPLength settings. X-ray diffraction analysis revealed a heteroepitaxial-like growth pattern with a sixfold symmetric diffraction pattern corresponding to GaN{10−10} planes. At a tPLength of 200 ms, the full width at half maximum of the rocking curve at GaN (0002) diffraction angle decreased to 1.6°. Optimizing the deposition rate per plasma discharge pulse with CPSD indicated the importance of selecting an optimal tPLength for achieving desirable crystalline properties in GaN film sputtering deposition.
研究了等离子体放电脉冲长度（tPLength）对使用高密度聚合等离子体溅射装置（CPSD）沉积在蓝宝石基底上的氮化镓薄膜结晶度的影响。研究涵盖了 1 到 200 ms 的 tPLength 值，基底温度保持在 200 °C。在所有 tPLength 设置下，GaN 薄膜都显示出沿 (0002) 平面的优先取向。X 射线衍射分析显示了一种异外延生长模式，其六倍对称衍射模式与 GaN{10-10} 平面相对应。当 tPLength 为 200 ms 时，GaN（0002）衍射角处的摇摆曲线半最大值全宽降至 1.6°。利用 CPSD 优化每个等离子体放电脉冲的沉积速率表明，在 GaN 薄膜溅射沉积过程中，选择最佳的 tPLength 对于获得理想的结晶特性非常重要。
{"title":"Effect of plasma discharge pulse length for GaN film crystallinity on sapphire substrate by high density convergent plasma sputtering device","authors":"Itsuki Misono, T. Motomura, T. Tabaru, Masato Uehara, Tetsuya Okuyama","doi":"10.1116/6.0003743","DOIUrl":"https://doi.org/10.1116/6.0003743","url":null,"abstract":"Plasma discharge pulse length (tPLength) was investigated for its impact on the crystallinity of GaN films deposited on a sapphire substrate using a high-density convergent plasma sputtering device (CPSD). The study covered tPLength values from 1 to 200 ms, maintaining the substrate temperature at 200 °C. GaN films showed preferential orientation along the (0002) plane for all tPLength settings. X-ray diffraction analysis revealed a heteroepitaxial-like growth pattern with a sixfold symmetric diffraction pattern corresponding to GaN{10−10} planes. At a tPLength of 200 ms, the full width at half maximum of the rocking curve at GaN (0002) diffraction angle decreased to 1.6°. Optimizing the deposition rate per plasma discharge pulse with CPSD indicated the importance of selecting an optimal tPLength for achieving desirable crystalline properties in GaN film sputtering deposition.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Exploring the thermochemical erosion mechanism and inhibiting the thermochemical erosion reaction is essential to improve the service life of the barrel weapon. Due to high temperature and supersonic environments of the barrel weapon, the current research on its thermochemical erosion has only stopped at the final failure moment. This paper designs an erosion analog device to simulate harsh launch environments and to investigate the erosion mechanism through a combination of removable samples. The removable samples consist of five types: artillery steel sample, Cr-plated coating sample, Cr-plated coating with laser shock peening sample, tantalum magnetron sputtering coating sample, and nano-enhanced coating sample. With 200 times erosion experiments, samples have appeared with different degrees of erosion acceleration, in which the Cr-plated coating with laser shock peening sample has the least cracks and the best corrosion inhibition performance. In addition, Cr-plated coating with laser shock peening samples with diameters of 80, 100, and 120 μm are designed, and the erosion experiments reveal that the 80 μm sample shows the best erosion inhibition performance.
{"title":"Inhibition of thermochemical erosion by different coatings attached to the barrel chamber at high temperature and supersonic environments","authors":"Shuli Li, Guolai Yang, Liqun Wang, Liguo Xue","doi":"10.1116/6.0003752","DOIUrl":"https://doi.org/10.1116/6.0003752","url":null,"abstract":"Exploring the thermochemical erosion mechanism and inhibiting the thermochemical erosion reaction is essential to improve the service life of the barrel weapon. Due to high temperature and supersonic environments of the barrel weapon, the current research on its thermochemical erosion has only stopped at the final failure moment. This paper designs an erosion analog device to simulate harsh launch environments and to investigate the erosion mechanism through a combination of removable samples. The removable samples consist of five types: artillery steel sample, Cr-plated coating sample, Cr-plated coating with laser shock peening sample, tantalum magnetron sputtering coating sample, and nano-enhanced coating sample. With 200 times erosion experiments, samples have appeared with different degrees of erosion acceleration, in which the Cr-plated coating with laser shock peening sample has the least cracks and the best corrosion inhibition performance. In addition, Cr-plated coating with laser shock peening samples with diameters of 80, 100, and 120 μm are designed, and the erosion experiments reveal that the 80 μm sample shows the best erosion inhibition performance.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141803702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The influence of high-temperature thermal annealing on silicon dangling bonds called K centers in Si-rich silicon nitride films grown in a single-wafer-type low-pressure chemical vapor deposition reactor with the SiH2Cl2-NH3 system at 750 °C has been investigated by combining thermal desorption spectroscopy (TDS), Fourier transform infrared spectroscopy-attenuated total reflection, spectroscopic ellipsometry, and electron spin resonance. In the TDS analysis, H2 desorption from the nitride films was detected above about 600 °C. It is found that thermal annealing at 750 and 900 °C caused a slight decrease in the K center density and a change in the g value of K centers, which are considered to be caused by changes in the atomic structure of the nitride films. On the other hand, thermal annealing at 1050 °C resulted in a substantial decrease in the K center density and the generation of paramagnetic defects with unprecedented characteristics. The findings in this study are expected to provide important guidelines for the design of manufacturing processes of nonvolatile memories.
通过结合热脱附光谱（TDS）、傅立叶变换红外光谱-衰减全反射、光谱椭偏仪和电子自旋共振，研究了高温热退火对在单晶片式低压化学气相沉积反应器中以 SiH2Cl2-NH3 体系在 750 ℃ 生长的富硅氮化硅薄膜中称为 K 中心的硅悬键的影响。在 TDS 分析中，检测到氮化物薄膜在约 600 °C 以上有 H2 解吸现象。研究发现，750 ℃ 和 900 ℃ 的热退火会导致 K 中心密度的轻微下降和 K 中心 g 值的变化，这被认为是氮化膜原子结构变化引起的。另一方面，1050 ℃ 的热退火导致 K 中心密度大幅下降，并产生了具有前所未有特性的顺磁缺陷。本研究的发现有望为非易失性存储器制造工艺的设计提供重要指导。
{"title":"Influence of high-temperature thermal annealing on paramagnetic point defects in silicon-rich silicon nitride films formed in a single-wafer-type low-pressure chemical vapor deposition reactor","authors":"Kiyoteru Kobayashi, Ryo Miyauchi, Kenshi Kimoto","doi":"10.1116/6.0003778","DOIUrl":"https://doi.org/10.1116/6.0003778","url":null,"abstract":"The influence of high-temperature thermal annealing on silicon dangling bonds called K centers in Si-rich silicon nitride films grown in a single-wafer-type low-pressure chemical vapor deposition reactor with the SiH2Cl2-NH3 system at 750 °C has been investigated by combining thermal desorption spectroscopy (TDS), Fourier transform infrared spectroscopy-attenuated total reflection, spectroscopic ellipsometry, and electron spin resonance. In the TDS analysis, H2 desorption from the nitride films was detected above about 600 °C. It is found that thermal annealing at 750 and 900 °C caused a slight decrease in the K center density and a change in the g value of K centers, which are considered to be caused by changes in the atomic structure of the nitride films. On the other hand, thermal annealing at 1050 °C resulted in a substantial decrease in the K center density and the generation of paramagnetic defects with unprecedented characteristics. The findings in this study are expected to provide important guidelines for the design of manufacturing processes of nonvolatile memories.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141806714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Immersion ellipsometry can break the well-known correlation between optical constants and thicknesses of ultrathin (<5–10 nm) films, allowing both to be determined. In immersion ellipsometry, ellipsometric data is acquired in air and liquid ambients, and the data sets are combined in the analysis. The contrast in index between the liquid and film adds information to the analysis that breaks the correlation between the film thickness and refractive index that exists for air-only measurements. We describe the theory and practice of immersion ellipsometry. We also discuss the use of multiwavelength immersion ellipsometry to measure the thicknesses and optical constants of two thin films: native oxide on silicon and an alkyl monolayer on that native oxide. The average thicknesses of the native oxide and chloro(dimethyl)octadecylsilane (CDMOS) monolayer were 1.526 ± 0.027 nm and 1.968 ± 0.057 nm, and their average indices of refraction at 633 nm were 1.519 ± 0.005 and 1.471 ± 0.004, respectively. The native oxide and CDMOS monolayer were also characterized with x-ray photoelectron spectroscopy (XPS) and contact angle goniometry. Both the XPS C 1 s peak and the water contact angle increased substantially after monolayer deposition. While immersion ellipsometry has been known for decades, its use has been limited, maybe due to a lack of awareness of the technique and/or the need to immerse the sample surface in a liquid that could be destructive if the sample is not compatible with the liquid. As ultrathin films become widely used in science technology, immersion ellipsometry should increase in importance.
浸入式椭偏仪可以打破超薄（<5-10 nm）薄膜的光学常数与厚度之间众所周知的相关性，从而可以同时测定两者。在浸入式椭偏仪中，椭偏仪数据分别在空气和液体环境中采集，并将数据集合并进行分析。液体和薄膜之间的折射率对比为分析增加了信息，打破了纯空气测量中薄膜厚度和折射率之间的相关性。我们介绍了浸入式椭偏仪的理论和实践。我们还讨论了使用多波长浸入式椭偏仪测量两层薄膜的厚度和光学常数：硅上的原生氧化物和原生氧化物上的烷基单层。原生氧化物和氯(二甲基)十八烷基硅烷（CDMOS）单层的平均厚度分别为 1.526 ± 0.027 nm 和 1.968 ± 0.057 nm，它们在 633 nm 波长处的平均折射率分别为 1.519 ± 0.005 和 1.471 ± 0.004。原生氧化物和 CDMOS 单层还利用 X 射线光电子能谱（XPS）和接触角测角仪进行了表征。单层沉积后，XPS C 1 s 峰值和水接触角都大幅增加。虽然浸入式椭偏仪已经有几十年的历史，但其应用一直很有限，这可能是由于人们对该技术缺乏了解，以及/或需要将样品表面浸入液体中，如果样品与液体不兼容，就会造成破坏。随着超薄薄膜在科学技术中的广泛应用，浸入式椭偏仪的重要性应该会增加。
{"title":"Immersion ellipsometry for the uncorrelated determination of ultrathin film thickness and index of refraction: Theory and examples","authors":"Samira Jafari, Blaine Johs, M. Linford","doi":"10.1116/6.0003511","DOIUrl":"https://doi.org/10.1116/6.0003511","url":null,"abstract":"Immersion ellipsometry can break the well-known correlation between optical constants and thicknesses of ultrathin (<5–10 nm) films, allowing both to be determined. In immersion ellipsometry, ellipsometric data is acquired in air and liquid ambients, and the data sets are combined in the analysis. The contrast in index between the liquid and film adds information to the analysis that breaks the correlation between the film thickness and refractive index that exists for air-only measurements. We describe the theory and practice of immersion ellipsometry. We also discuss the use of multiwavelength immersion ellipsometry to measure the thicknesses and optical constants of two thin films: native oxide on silicon and an alkyl monolayer on that native oxide. The average thicknesses of the native oxide and chloro(dimethyl)octadecylsilane (CDMOS) monolayer were 1.526 ± 0.027 nm and 1.968 ± 0.057 nm, and their average indices of refraction at 633 nm were 1.519 ± 0.005 and 1.471 ± 0.004, respectively. The native oxide and CDMOS monolayer were also characterized with x-ray photoelectron spectroscopy (XPS) and contact angle goniometry. Both the XPS C 1 s peak and the water contact angle increased substantially after monolayer deposition. While immersion ellipsometry has been known for decades, its use has been limited, maybe due to a lack of awareness of the technique and/or the need to immerse the sample surface in a liquid that could be destructive if the sample is not compatible with the liquid. As ultrathin films become widely used in science technology, immersion ellipsometry should increase in importance.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anjar Anggraini Harumningtyas, Tomoko Ito, Hidekazu Kita, Joe Kodama, Takashi Kaito, S. Hamaguchi
A recent in vivo study [Kodama et al., Sci. Rep. 11, 1 (2021)] showed that porous artificial bones coated with amine-containing polymers deposited by plasma-enhanced chemical vapor deposition (PECVD) significantly enhanced bone regeneration. This article reports the chemical and physical properties of amine plasma polymers (PPs) formed under the same deposition conditions, including the film stability for up to two months, the effects of sterilization on the chemical compositions of the films, and the penetration of amine PPs into the inner surfaces of interconnected microscopic pores of the amine PP-coated porous artificial bone. It was found that, immediately after the plasma polymerization process, approximately 20% of nitrogen atoms on the surface of the deposited amine PP formed primary amines. However, the value decreased to approximately 5% over one month if the sample was exposed to ambient air. The relative concentration of primary amines also decreased to a similar value after the sample was sterilized by autoclaving or ethylene oxide gas. Molecular dynamics simulations were used to examine possible formation mechanisms of nitriles in deposit films under the PECVD conditions and found that ion impact can significantly reduce the nitrile content.
{"title":"Amine plasma polymers deposited on porous hydroxyapatite artificial bone with bipolar pulsed discharges","authors":"Anjar Anggraini Harumningtyas, Tomoko Ito, Hidekazu Kita, Joe Kodama, Takashi Kaito, S. Hamaguchi","doi":"10.1116/6.0003724","DOIUrl":"https://doi.org/10.1116/6.0003724","url":null,"abstract":"A recent in vivo study [Kodama et al., Sci. Rep. 11, 1 (2021)] showed that porous artificial bones coated with amine-containing polymers deposited by plasma-enhanced chemical vapor deposition (PECVD) significantly enhanced bone regeneration. This article reports the chemical and physical properties of amine plasma polymers (PPs) formed under the same deposition conditions, including the film stability for up to two months, the effects of sterilization on the chemical compositions of the films, and the penetration of amine PPs into the inner surfaces of interconnected microscopic pores of the amine PP-coated porous artificial bone. It was found that, immediately after the plasma polymerization process, approximately 20% of nitrogen atoms on the surface of the deposited amine PP formed primary amines. However, the value decreased to approximately 5% over one month if the sample was exposed to ambient air. The relative concentration of primary amines also decreased to a similar value after the sample was sterilized by autoclaving or ethylene oxide gas. Molecular dynamics simulations were used to examine possible formation mechanisms of nitriles in deposit films under the PECVD conditions and found that ion impact can significantly reduce the nitrile content.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alaina Thompson, William Limestall, Art Nelson, Daniel T. Olive, Jeff Terry
Photoelectron spectroscopy allows for the investigation of the electronic structure and chemical bonding of actinide elements and their compounds, providing insights into oxidation states, chemical environments, and electronic configurations. This knowledge can aid in comprehending reactivity, stability, and other properties of actinide materials, which is essential for ensuring safe handling, storage, and disposal in nuclear applications. We have reviewed a number of results in actinide core-level photoemission studies, with a particular focus on x-ray photoemission spectroscopy (XPS) techniques. Actinides, due to their inherent radioactivity, have not been as well studied with XPS as have other segments of the periodic table. Given the inherent safety concerns, equipment requirements, and short isotopic lifetimes associated with actinide research, we outline the strategies and precautions necessary for conducting successful and safe XPS experiments on these elements. Core-level photoemission can be a powerful proven tool for investigating the electronic structure, chemical bonding behaviors, and physical properties of actinides, providing valuable insights into an incredibly complex behavior of these systems. We highlight key findings from recent studies that demonstrate the potential of core-level photoemission in uncovering the unique properties of actinides and their compounds. Finally, we identify current knowledge gaps and future research directions that could enhance our understanding of actinide chemistry and physics.
光电子能谱可以研究锕系元素及其化合物的电子结构和化学键，深入了解氧化态、化学环境和电子构型。这些知识有助于理解锕系元素材料的反应性、稳定性和其他特性，这对于确保核应用中的安全处理、储存和处置至关重要。我们回顾了锕系元素核心级光致发光研究的多项成果，尤其侧重于 X 射线光致发光光谱（XPS）技术。锕系元素由于其固有的放射性，在 XPS 方面的研究不如周期表中的其他元素。考虑到与锕系元素研究相关的固有安全问题、设备要求和较短的同位素寿命，我们概述了对这些元素进行成功和安全的 XPS 实验所必需的策略和预防措施。核心级光致发光是研究锕系元素的电子结构、化学键行为和物理性质的有力工具，可为了解这些系统极其复杂的行为提供宝贵的见解。我们重点介绍了近期研究的主要发现，这些发现证明了核心级光致发光在揭示锕系元素及其化合物独特性质方面的潜力。最后，我们指出了当前的知识空白和未来的研究方向，这些研究方向可以增强我们对锕系元素化学和物理的理解。
{"title":"Review of actinide core-level photoemission","authors":"Alaina Thompson, William Limestall, Art Nelson, Daniel T. Olive, Jeff Terry","doi":"10.1116/6.0003534","DOIUrl":"https://doi.org/10.1116/6.0003534","url":null,"abstract":"Photoelectron spectroscopy allows for the investigation of the electronic structure and chemical bonding of actinide elements and their compounds, providing insights into oxidation states, chemical environments, and electronic configurations. This knowledge can aid in comprehending reactivity, stability, and other properties of actinide materials, which is essential for ensuring safe handling, storage, and disposal in nuclear applications. We have reviewed a number of results in actinide core-level photoemission studies, with a particular focus on x-ray photoemission spectroscopy (XPS) techniques. Actinides, due to their inherent radioactivity, have not been as well studied with XPS as have other segments of the periodic table. Given the inherent safety concerns, equipment requirements, and short isotopic lifetimes associated with actinide research, we outline the strategies and precautions necessary for conducting successful and safe XPS experiments on these elements. Core-level photoemission can be a powerful proven tool for investigating the electronic structure, chemical bonding behaviors, and physical properties of actinides, providing valuable insights into an incredibly complex behavior of these systems. We highlight key findings from recent studies that demonstrate the potential of core-level photoemission in uncovering the unique properties of actinides and their compounds. Finally, we identify current knowledge gaps and future research directions that could enhance our understanding of actinide chemistry and physics.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141811901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The resonant photoelectron spectroscopy (ResPes) of new and aged δ-Pu(Ga) is reassessed by using the small oxygen contaminant peaks as an independent and quantitative check upon conventional cross-photon-energy normalization. Good agreement is found between the measured oxygen intensities and the atomic cross section calculations. Consistent with earlier analyses, the radiation induced damage in the aged samples is found to compress and sharpen the 5f peaks. This is associated with increased localization of the 5f bands, corresponding to the 5f density of states calculations that show a narrowing of 5f bandwidth with cluster size diminishment.
{"title":"Quantifying the resonant photoemission of radiation damaged Pu","authors":"J. G. Tobin, S.-W. Yu, B. W. Chung","doi":"10.1116/6.0003764","DOIUrl":"https://doi.org/10.1116/6.0003764","url":null,"abstract":"The resonant photoelectron spectroscopy (ResPes) of new and aged δ-Pu(Ga) is reassessed by using the small oxygen contaminant peaks as an independent and quantitative check upon conventional cross-photon-energy normalization. Good agreement is found between the measured oxygen intensities and the atomic cross section calculations. Consistent with earlier analyses, the radiation induced damage in the aged samples is found to compress and sharpen the 5f peaks. This is associated with increased localization of the 5f bands, corresponding to the 5f density of states calculations that show a narrowing of 5f bandwidth with cluster size diminishment.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ion beams are used in x-ray photoelectron spectroscopy (XPS) to clean samples and perform compositional sputter depth profiles. The purpose of this article is to compile good practice, recommendations, and useful information related to the use of argon ion sources for inexperienced users of XPS instrumentation. The most used type of ion source generates monoatomic argon ions at a range of energies from a fixed direction relative to the instrument. The angle and direction of the ion beam with respect to the surface are normally altered by manipulating the sample, and this may involve tilting the sample to change the angle of incidence or rotating the sample to change the azimuthal incidence angle. Atomic argon ion beams cause damage to the structure of the material surface, which may exhibit itself as a change in stoichiometry or topography as well as the implantation of argon atoms. Therefore, caution is required in the interpretation of XPS depth profiles. Gas cluster ion sources offer new possibilities and choices to XPS users. Gas cluster sources enable the sputtering of organic materials with high yield in comparison to inorganic materials and offer the potential for nearly damage-free depth profiling of delicate organic materials as well as low damage cleaning of inorganic materials. It may be possible to use argon clusters to reduce damage during the depth profiling of inorganic materials, but there is currently insufficient evidence to make any general recommendations.
离子束在 X 射线光电子能谱（XPS）中用于清洁样品和进行成分溅射深度剖面分析。本文旨在为 XPS 仪器的无经验用户汇编与使用氩离子源有关的良好做法、建议和有用信息。最常用的离子源类型是从相对于仪器的固定方向产生一系列能量的单原子氩离子。离子束相对于表面的角度和方向通常通过操作样品来改变，这可能包括倾斜样品以改变入射角，或旋转样品以改变方位入射角。原子氩离子束会对材料表面结构造成破坏，可能表现为化学计量或形貌的改变以及氩原子的植入。因此，在解释 XPS 深度剖面时需要谨慎。气簇离子源为 XPS 用户提供了新的可能性和选择。与无机材料相比，气簇离子源能以高产率溅射有机材料，并有可能对脆弱的有机材料进行几乎无损伤的深度剖面分析，以及对无机材料进行低损伤清洗。在对无机材料进行深度剖析时，使用氩气簇可能会减少损坏，但目前还没有足够的证据提出任何一般性建议。
{"title":"Practical guides for x-ray photoelectron spectroscopy: Use of argon ion beams for sputter depth profiling and cleaning","authors":"Alexander G. Shard, M. Baker","doi":"10.1116/6.0003681","DOIUrl":"https://doi.org/10.1116/6.0003681","url":null,"abstract":"Ion beams are used in x-ray photoelectron spectroscopy (XPS) to clean samples and perform compositional sputter depth profiles. The purpose of this article is to compile good practice, recommendations, and useful information related to the use of argon ion sources for inexperienced users of XPS instrumentation. The most used type of ion source generates monoatomic argon ions at a range of energies from a fixed direction relative to the instrument. The angle and direction of the ion beam with respect to the surface are normally altered by manipulating the sample, and this may involve tilting the sample to change the angle of incidence or rotating the sample to change the azimuthal incidence angle. Atomic argon ion beams cause damage to the structure of the material surface, which may exhibit itself as a change in stoichiometry or topography as well as the implantation of argon atoms. Therefore, caution is required in the interpretation of XPS depth profiles. Gas cluster ion sources offer new possibilities and choices to XPS users. Gas cluster sources enable the sputtering of organic materials with high yield in comparison to inorganic materials and offer the potential for nearly damage-free depth profiling of delicate organic materials as well as low damage cleaning of inorganic materials. It may be possible to use argon clusters to reduce damage during the depth profiling of inorganic materials, but there is currently insufficient evidence to make any general recommendations.","PeriodicalId":509398,"journal":{"name":"Journal of Vacuum Science & Technology A","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141815362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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