Journal of Vacuum Science and Technology最新文献

{"title":"Nanoscale strain gauges on flexible polymer substrates","authors":"Devin K. Brown, Isha Lodhi, Biya Haile, David R. Myers, Wilbur A. Lam, Oliver Brand","doi":"10.1116/6.0003030","DOIUrl":"https://doi.org/10.1116/6.0003030","url":null,"abstract":"Biological cell force is important for proper cell and tissue function and can be an indicator of disease. Therefore, measuring cell force has potential in disease diagnosis and treatment. However, biological cell force measurement approaches are limited and typically slow due to the analysis of optical images before and after cell application or other methods that have low throughput. This work seeks to overcome this bottleneck by the use of nanoscale strain gauges which can measure cell forces as an electrical signal in real time, as well as being able to be scaled to measure tens of thousands of cells, simultaneously. This paper presents the design, COMSOL simulation, fabrication, as well as electrical and mechanical testing of gold nanometer scale strain gauges embedded in soft polydimethylsiloxane (PDMS) using a sacrificial aluminum layer method. A process flow using an aluminum sacrificial layer is presented, which successfully fabricated gold strain gauges with 100 nm dimensions in soft PDMS polymer and have been used to measure strain applied to the PDMS surface. Compressive strains ranging from 0.4% to 1.7% in the PDMS surface, corresponding to forces of 718 nN to 2.0 μN have been detected with resistance changes of 1%–8%. To the best of our knowledge, these are the smallest metal strain gauges to be made on soft polymers and is a promising new approach for biological cell force measurement.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136262550","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}

{"title":"Deposition and optical properties investigation of components for multilayer electrochromic system","authors":"Janusz Rybak, Konstanty W. Marszalek","doi":"10.1116/6.0003138","DOIUrl":"https://doi.org/10.1116/6.0003138","url":null,"abstract":"Electrochromic materials are materials that change their optical properties under the influence of an applied electrical potential. They can be based on different types of electrochromes, ranging from metal oxides (e.g., WO3, MO3, TiO, or NiO) to organic materials (such as SmPc2, EuPc2, or YbPc2). The choice of electrochromic material determines the subsequent choice of components, such as the electrolyte, also called the fast ion conductor, and the ion storage layer. In this paper, the authors present methods for the deposition of the individual functional layers of the electrochromic system, together with the parameters of the deposition processes. The construction of the high-vacuum apparatus on which the layers were deposited is presented. The results of structural and optical measurements of the deposited layers are also presented.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136381308","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}

{"title":"High-performance normally off AlGaN/GaN high electron mobility transistor with p-type h-BN cap layer","authors":"Nan Wang, Haiping Wang, Zhuokun He, Xiaohui Gao, Dunjun Chen, Yukun Wang, Haoran Ding, Yufei Yang, Qianyu Hou, Wenhong Sun","doi":"10.1116/5.0169900","DOIUrl":"https://doi.org/10.1116/5.0169900","url":null,"abstract":"Normally off AlGaN/GaN high electron mobility transistors (HEMTs) with p-type gates are attracting increasing attention due to their high safety and low power loss in the field of power switching. In this work, to solve the Mg difficult activating problem of the conventional p-GaN gate AlGaN/GaN HEMTs, we propose an advanced design for the normally off AlGaN/GaN HEMT with a p-type hexagonal boron nitride (h-BN) gate cap layer to effectively manipulate the channel transport of the device. The simulation results demonstrate that the p-hBN gate cap HEMTs yield superior performance over conventional p-GaN gate HEMTs in terms of output current and breakdown voltage, which can be attributed to the deeper potential well formation at the AlGaN/GaN interface and more accumulation of holes located at the p-hBN/AlGaN interface. Moreover, we investigate the effect of bandgap variation on device performance, taking into account that the exact bandgap of h-BN remains under debate. Herein, valuable insights into h-BN cap-gate E-mode AlGaN/GaN HEMT devices are provided, which could serve as a useful reference for the future development of robust III-nitride material power electronic devices.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135617887","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}

{"title":"Atomic-scale imaging and spectroscopy via scanning probe microscopy: An overview","authors":"Saima A. Sumaiya, Mehmet Z. Baykara","doi":"10.1116/6.0002889","DOIUrl":"https://doi.org/10.1116/6.0002889","url":null,"abstract":"Atomic-scale characteristics of surfaces, including their structure, chemical reactivity, and electronic properties, determine their roles in multiple fields of science and technology, e.g., as coatings, catalysts, and device components. As such, it is of utmost importance to study the atomic arrangement and atomic-scale physico-chemical properties of surfaces in real space in a robust and reliable manner. A powerful technique for achieving this goal is scanning probe microscopy (SPM). Here, we present an overview of SPM-based techniques for atomic-resolution surface imaging and spectroscopy and highlight selected advances in the field. We also discuss current challenges of SPM-based techniques for atomic-resolution surface studies.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135729620","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}

{"title":"Investigation of polymer template removal techniques in three-dimensional thin-shell nanolattices","authors":"Vijay Anirudh Premnath, Chih-Hao Chang","doi":"10.1116/6.0003036","DOIUrl":"https://doi.org/10.1116/6.0003036","url":null,"abstract":"Recent advanced in nanofabrication has enabled various opportunities for research and development in photonic crystals, integrated circuits, and nanostructured materials. One interesting class of emerging materials is nanolattices, which consist of hollow-core, thin-shell elements fabricated using thin-film deposition on three-dimensional polymer templates. While many applications of nanolattices have been demonstrated, the residual polymer in the nanolattice can be problematic and is not well understood. This research investigates the effectiveness of different template removal techniques, including oxygen plasma etching, solvent dissolution, and thermal desorption. The rates and effectiveness of resist removal for the different techniques are quantified using spectroscopic ellipsometry, which enables precise measurement of the effective refractive index and calculation of the residual polymer. A three-phase Maxwell–Garnett effective medium model is used to calculate the residual polymer in the nanolattices. This work demonstrates that the temperature treatment is most effective at template removal, which can be used to improve the fabrication of nanolattices for mechanical, optical, and thermal applications.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136032633","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}

{"title":"New coating with superior corrosion and wear performances: Parylene C/CrN duplex coating","authors":"Xiaoyan Guan, Siwen Cui, Yiwei Cao, Liuxue Zhang","doi":"10.1116/6.0002982","DOIUrl":"https://doi.org/10.1116/6.0002982","url":null,"abstract":"Growth defects such as pores during preparation restrict the service life and wide applications of CrN coating. To improve the corrosion and tribological behaviors of CrN coatings, in this work, the parylene C (PC)/CrN duplex coatings with different CrN layer thicknesses were fabricated, combining chemical vapor deposition and physical vapor deposition technologies. The surface morphologies and chemical bonds of as-deposited coatings were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively. The corrosion and wear behaviors of the CrN coatings without and with PC layers in the seawater environment were evaluated using an electrochemical workstation and a tribometer, respectively. The results showed that the surface of the PC film was relatively compact, which was well bounded to the CrN layer. The corrosion current density of the PC/CrN duplex coating is low to 10−9 A/cm2, which is reduced by one order of magnitude compared to the single CrN coating. As the thickness of the CrN layer increases, the corrosion potential of the PC/CrN duplex coating decreases and the corrosion current density slightly increases, which may be ascribed to the increased defects of the CrN layer, which debased the corrosion resistance. Furthermore, the steady friction coefficients of PC/CrN duplex coatings are all below 0.05, which are significantly lower compared to the single CrN coatings. The lowest wear rate of the PC/CrN duplex coating is approximately 1.31 × 10−6 mm3/N m, presenting excellent wear resistance. Compared to the single CrN coating, the dense PC film can not only seal the pores and other defects on the CrN surface, but also prevent the permeation and penetration of corrosive seawater inside the coating, which contributes to the superior corrosion resistance of the PC/CrN duplex coating. The low friction and high wear resistance of the PC/CrN duplex coating could be ascribed to the self-lubricating property, the PC film, and its good protective performance as a surface layer, as well as the generation of CaCO3 and Mg(OH)2 lubrication components during the wear process. In summary, the PC films can remarkably improve the corrosion and tribological performance of the CrN coating. The excellent corrosion resistance and wear resistance of the PC/CrN duplex coating make it a good candidate material for applications in marine environments.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112860","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}

{"title":"Identification of dust particles on a periodic nanostructured substrate using scanning electron microscope imaging","authors":"Andrew Tunell, Lauren Micklow, Nichole Scott, Stephen Furst, Chih-Hao Chang","doi":"10.1116/6.0003043","DOIUrl":"https://doi.org/10.1116/6.0003043","url":null,"abstract":"Dust-mitigating surfaces typically consist of high-aspect-ratio structures that separate particles from resting on the bulk material, thereby limiting adhesion due to short-range van der Waals forces. These surfaces can find uses in solar-panel coatings and a variety of dust-resistant optics. The current method for quantifying surface contamination is optical microscopy, but this method is inadequate for observing particles at the submicrometer scale due to the diffraction limit. Furthermore, regardless of the microscopy technique, particle identification becomes problematic as the particle contaminates approach the same length scale of the surface structures. In this work, we demonstrate a method to identify micro-/nanoparticle contaminates on nanostructured surfaces using electron microscopy and image processing. This approach allows the characterization of particles that approach the length scale of the surface structures. Image processing, including spectrum filters and edge detection, is used to remove the periodic features of the surface nanostructure to omit them from the particle counting. The detection of these small particles using electron microscopy leads to an average of 5.62 particles/100 μm2 detected compared to 0.63 particles/100 μm2 detected for the traditional confocal optical detection method. Beyond dust-mitigation nanostructures, the demonstrated particle detection technique can find applications in nanobiology, the detection of ice nucleation on a structured surface, and semiconductor mask inspections.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135858582","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}

{"title":"<i>In situ</i> metrology of direct-write laser ablation using optical emission spectroscopy","authors":"Briana Cuero, Kun-Chieh Chien, Chih-Hao Chang","doi":"10.1116/6.0003031","DOIUrl":"https://doi.org/10.1116/6.0003031","url":null,"abstract":"Direct-write laser ablation is an effective manufacturing method for etching complex microscale patterns, especially on hard ceramics such as sapphire that are difficult to machine using traditional mechanical or micromachining methods. However, the variability of the laser–matter interaction causes inconsistencies that prevent this process from moving beyond the research realm. This work presents the real-time monitoring of the ablation process in sapphire using optical emission spectroscopy to assess the key wavelengths that exhibit strong correlations to the fabricated features. In this process, a focused ultrafast laser is used to create microscale features and morphological changes in sapphire substrates, which are studied by a subsequent wet etching in a hydrogen fluoride solution. The etched sapphire samples are observed to have amorphous sapphire removed, resulting in microstructures with higher profile fidelity. Furthermore, principal component analysis of the measured spectral obtained during the etch process indicates that the emission from a few key wavelengths exhibits strong correlations to the etched sapphire patterns. This result indicates that the use of data-driven techniques to assess the spectral emissions of direct-write laser ablation can be a useful tool in developing in situ metrology methods for laser-matter interactions.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136012993","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}

{"title":"Fabrication of hierarchical nanostructures using binary colloidal nanosphere assembly","authors":"Ethan Flores, Saurav Mohanty, Andrew Tunell, Chih-Hao Chang","doi":"10.1116/6.0003027","DOIUrl":"https://doi.org/10.1116/6.0003027","url":null,"abstract":"In this paper, we investigate the self-assembly of hierarchical nanostructures using monodispersed nanospheres with two different diameters. Our approach is to use a two-step method where the assembly of larger 200 nm nanospheres is used to direct the assembly of smaller 50 nm particles. This self-assembly technique is based on Langmuir–Blodgett assembly and has low equipment cost when compared with traditional lithography methods. We examine the effects of substrate surface treatment, solution concentration ratio, and spin speeds on the quality of the hierarchical assembly. The fabricated samples are examined using optical and scanning electron microscopy to investigate assembly yield. Various defect types are identified and mitigated by process control. The ability to create more complex assembly can result in smaller features and can enhance the performance of photonics and nanostructured surfaces.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136012837","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}

{"title":"X-ray multi-scale microfabrication system and x-ray imaging evaluation system all in one beamline","authors":"Kanta Yamamoto, Yuichi Utsumi, Ikuya Sakurai, Ikuo Okada, Kenji Hanada, Hidehiro Ishizawa, Masahiro Takeo, Taki Watanabe, Sho Amano, Satoru Suzuki, Koji Sumitomo, Akinobu Yamaguchi","doi":"10.1116/6.0003021","DOIUrl":"https://doi.org/10.1116/6.0003021","url":null,"abstract":"We have completed a system that can achieve both deep x-ray lithography and submicron x-ray lithography with a single beamline by introducing the combination of x-ray plane and cylindrical mirrors. This x-ray lithography system can provide a large-scale microfabrication processing with 210 × 300 mm2 (A4 size). To exploit multiscale lithography, the beamline has a beam transport vacuum duct with a two-stage stacked structure and a 5-axis stage. This two-stage stacked structure allows us to fabricate both micron scale structures with high aspect ratios and submicron scale structures using the same beamline. In addition, x-ray imaging and computer tomography (CT) system are connected to the x-ray lithography system for nondestructive inspection and evaluation of the fabricated microstructures. The x-ray imaging system constructed this study has a relatively low energy range of x-ray energy in the beamline, which is in the range of 2–15 keV or less. Therefore, relatively good absorption contrast can be obtained for plastic materials, biomaterials, and the like. Since nondestructive imaging of the processed shape by x-ray lithography is possible, it is a very useful system in processing and evaluation can be performed simultaneously. This system also enables us to obtain the live images with keeping the creature alive in liquid using an indirect x-ray imaging system which converts x-ray images to visible light images through the fluorescent plate.","PeriodicalId":17571,"journal":{"name":"Journal of Vacuum Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136210848","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}