Дисертації з теми "Focused Ion Beam machining"
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Evans, R. "Focused ion beam machining of hard materials for micro engineering applications." Thesis, Cranfield University, 2009. http://dspace.lib.cranfield.ac.uk/handle/1826/4417.
Повний текст джерелаChitsaz, Charandabi Sahand. "Development of a Lorentz force drive system for a torsional paddle microresonator using Focused Ion Beam machining." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/4872/.
Повний текст джерелаZhang, Haoyu. "Application of focused ion beam for micro-machining and controlled quantum dot formation on patterned GaAs substrate." Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/6408/.
Повний текст джерелаCastro, Olivier de. "Development of a Versatile High-Brightness Electron Impact Ion Source for Nano-Machining, Nano-Imaging and Nano-Analysis." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS468/document.
Повний текст джерелаHigh brightness low energy spread (ΔE) ion sources are needed for focused ion beam nano-applications in order to get a high lateral resolution while having sufficiently high ion beam currents to obtain reasonable erosion rates and large secondary electron/ion yields. The objectives of this thesis are: the design of an electron impact ion source, a reduced brightness Br of 10³ – 10⁴ A m⁻² sr⁻ ¹ V⁻ ¹ with an energy distribution spread ΔE ≲ 1 eV and a versatile ion species choice. In a first evaluated concept an electron beam is focussed in between two parallel plates spaced by ≲1 mm. A micron sized ionisation volume is created above an extraction aperture of a few tens of µm. By using a LaB₆ electron emitter and the ionisation region with a pressure around 0.1 mbar, Br is close to 2.10² A m⁻² sr ⁻ ¹ V ⁻ ¹ with source sizes of a few µm, ionic currents of a few nA for Ar⁺/Xe⁺/O₂ ⁺ and the energy spread being ΔE < 0.5 eV. The determined Br value is still below the minimum targeted value and furthermore the main difficulty is that the needed operation pressure for the LaB₆ emitter cannot be achieved across the compact electron column and therefore a prototype has not been constructed. The second evaluated source concept is based on the idea to obtain a high current ion beam having a source size and half-opening beam angle similar to the first concept, but changing the electron gas interaction and the ion collection. Theoretical and experimental studies are used to evaluate the performance of this second source concept and its usefulness for focused ion beam nano-applications
Latif, Adnan. "Nanofabrication using focused ion beam." Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/34605.
Повний текст джерелаNaik, Jay Prakash. "Nanowires fabricated by Focused Ion Beam." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4638/.
Повний текст джерелаWong, Ka Chun. "Focused Ion Beam Nanomachining of Thermoplastic Polymers." Thesis, North Carolina State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3538536.
Повний текст джерелаCommercially available Ga+ focused ion beam (FIB) instruments with nanometer size probe allows for in situ materials removal (sputtering) and addition (deposition) on a wide range of material. These spatially precise processes have enabled a wide range of nanofacbrication operations (e.g. specimen preparation for analysis by scanning electron microscope, transmission electron microscope, and secondary ion mass spectrometer). While there exists an established knowledge of FIB methods for sample preparation of hard materials, but FIB methodology remain underdeveloped for soft materials such as biological and polymeric materials.
As FIB is increasingly utilized for specimen preparation of polymeric materials, it is becoming necessary to formulate an information base that will allow established FIB techniques to be generalized to this spectrum of materials. A thorough understanding of the fundamental ion-solid interactions that govern the milling process can be instrumental. Therefore, in an effort to make the existing procedures more universally applicable, the interrelationships between target material, variable processing parameters, and process efficiency of the milling phenomena are examined. The roles of beam current, distance (i.e. step size) between successive FIB beam dwell and the time it spent at each dwell point (i.e. pixel dwell time) are considered as applied to FIB nanomachining of four different thermoplastic polymers: 1. low density polyethylene (LDPE), 2. high density polyethylene (HDPE), 3. Polystyrene (PS), and 4. nylon 6 (PA6). Careful characterization of such relationships is used to explain observed phenomena and predict expected milling behaviors, thus allowing the FIB to be used more efficiently with reproducible results. Applications involving different types of polymer composite fiber are presented.
Sabouri, Aydin. "Nanofabrication by means of focused ion beam." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5987/.
Повний текст джерелаDella, Ratta Anthony D. (Anthony David). "Focused ion beam induced deposition of copper." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12418.
Повний текст джерелаShedd, Gordon M. 1954. "Focused ion beam assisted deposition of gold." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14947.
Повний текст джерелаMICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.
Bibliography: leaves 75-76.
by Gordon M. Shedd.
M.S.
Wang, H. "Focused-ion-beam growth of nanomechanical resonators." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1417006/.
Повний текст джерелаHadfield, Robert Hugh. "Josephson junctions fabricated by focused ion beam." Thesis, University of Cambridge, 2002. https://www.repository.cam.ac.uk/handle/1810/104789.
Повний текст джерелаMoseley, Richard William. "Focused ion beam fabricated non-equilibrium superconducting devices." Thesis, University of Cambridge, 2000. https://www.repository.cam.ac.uk/handle/1810/183624.
Повний текст джерелаPerez, Martinez Carla S. (Carla Sofia). "Characterization of ionic liquid ion sources for focused ion beam applications." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82506.
Повний текст джерелаThis thesis was scanned as part of an electronic thesis pilot project.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 79-82).
In the Focused Ion Beam (FIB) technique, a beam of ions is reduced to nanometer dimensions using dedicated optics and directed to a substrate for patterning. This technique is widely used in micro- and nanofabrication for etching, material deposition, microscopy, and chemical surface analysis. Traditionally, ions from metals or noble gases have been used for FIB, but it may be possible to diversify FIB applications by using ionic liquids. In this work, we characterize properties of an ionic liquid ion source (ILIS) relevant for FIB and recommend strategies for FIB implementation. To install ILIS in FIB, it is necessary to demonstrate single beam emission, free of neutral particles. Beams from ILIS contain a fraction of neutral particles, which could be detrimental for FIB as they are not manipulated by ion optics and could lead to undesired sample modification. We estimate the neutral particle fraction in the beam via retarding potential analysis, and use a beam visualization tool to determine that most of the neutral population is located at the center of the beam; the neutral population might then be eliminated using filtering. The same instrument is used to determine the transition of the source from single to multiple beam emission as the extraction voltage is increased. These studies should guide in the design of the optical columns for an ILIS-based FIB.
by Carla S. Perez Martinez.
S.M.
Bischoff, Lothar, and Jochen Teichert. "Focused Ion Beam Sputtering of Silicon and Related Materials." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-30797.
Повний текст джерелаHung, Wen-Chang. "Applications of a high resolution focused ion beam system." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531112.
Повний текст джерелаFunatsu, Jun. "Laser-assisted focused-ion-beam-induced deposition of copper." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/32617.
Повний текст джерелаSee, Un Siong Patrick. "In-situ focused ion beam patterned resonant tunnelling diodes." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624475.
Повний текст джерелаBischoff, Lothar, and Jochen Teichert. "Focused Ion Beam Sputtering of Silicon and Related Materials." Forschungszentrum Rossendorf, 1998. https://hzdr.qucosa.de/id/qucosa%3A21906.
Повний текст джерелаLi, Libing. "Strategies for secondary ion yield enhancements in focused ion beam secondary ion mass spectrometry." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/11806.
Повний текст джерелаTurnbull, Susan B. "Characterisation of focused ion beam nanostructures by transmission electron microscopy." Thesis, University of Glasgow, 2009. http://theses.gla.ac.uk/572/.
Повний текст джерелаWang, Xiaohu, and 王小虎. "Optical studies of focused ion beam fabricated GaN microstructures andnanostructures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47153428.
Повний текст джерелаpublished_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
McGrouther, Damien R. "Effects of focused ion beam irradiation on thin ferromagnetic films." Thesis, University of Glasgow, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410644.
Повний текст джерелаYasaka, Anto. "Feasibility study of spatial-phase-locked focused-ion-beam lithography." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/32663.
Повний текст джерелаTian, Zhipeng. "Nanopore/Nanotube Pattern Formation through Focused Ion Beam Guided Anodization." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/46207.
Повний текст джерелаMaster of Science
CHENG, JI. "FOCUSED ION BEAM FABRICATION OF PHOTONIC STRUCTURES FOR OPTICAL COMMUNICATIONS." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1023127713.
Повний текст джерелаCHYR, YEONG-NING. "THE PHOTONIC APPLICATIONS OF FOCUSED ION BEAM MICROMACHINGING ON GaN." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin987430536.
Повний текст джерелаHadjikhani, Ali. "Nanofabrication and Spectroscopy of Magnetic Nanostructures Using a Focused Ion Beam." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2536.
Повний текст джерелаHussain, Tahir. "Novel impurity distributions in GaAs devices by focused ion beam implantation." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241086.
Повний текст джерелаVelkova, Valentina. "Focused ion beam technology : implementation in manufacturing platforms and process optimisation." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/10352/.
Повний текст джерелаCooper, D. "Off-axis electron holography of focused ion beam prepared semiconductor devices." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597966.
Повний текст джерелаPhilipp, Peter. "Phase transformation in tetrahedral amorphous carbon by focused ion beam irradiation." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-136547.
Повний текст джерелаSu, Jong Hea Roland. "An analytical and fundamental study of focused ion beam optical spectroscopy." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388042.
Повний текст джерелаSun, Jining. "Deterministic fabrication of micro- and nano-structures by focused ion beam." Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2528.
Повний текст джерелаNeusser, Gregor [Verfasser]. "Advanced focused ion beam methods for prototyping and analytical applications / Gregor Neusser." Ulm : Universität Ulm, 2018. http://d-nb.info/1173791051/34.
Повний текст джерелаVijendran, Sanjay. "Fabrication of three-dimensional semiconductor devices using focused ion molecular beam epitaxy." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621997.
Повний текст джерелаLee, Boon Kwee. "OPTICAL STORAGE IN ERBIUM DOPED GALLIUM NITRIDE USING FOCUSED ION BEAM NANOFABRICATION." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin985883067.
Повний текст джерелаLuxmoore, Issac J. "Micro-electronic device fabrication using advanced focused ion beam and related techniques." Thesis, University of Sheffield, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489138.
Повний текст джерелаPuretz, Joseph. "A theoretical and experimental study of liquid metal ion sources and their application to focused ion beam technology /." Full text open access at:, 1988. http://content.ohsu.edu/u?/etd,182.
Повний текст джерелаBecherer, Markus [Verfasser]. "Nanomagnetic Logic in Focused Ion Beam Engineered Co/Pt Multilayer Films / Markus Becherer." Aachen : Shaker, 2011. http://d-nb.info/1072592673/34.
Повний текст джерелаCollins, Clair Louise. "Analytical electron microscopy of HSLA steels prepared using a focused ion beam system." Thesis, University of Glasgow, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412940.
Повний текст джерелаSargent, Laurence John. "Performance enhancement in vertical-cavity surface-emitting lasers using focused ion beam etching." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269231.
Повний текст джерелаYuan, Hui. "3D morphological and crystallographic analysis of materials with a Focused Ion Beam (FIB)." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0134/document.
Повний текст джерелаThe aim of current work is to optimize the serial-sectioning based tomography in a dual-beam focused ion beam (FIB) microscope, either by imaging in scanning electron microscopy (so-called FIB-SEM tomography), or by electron backscatter diffraction (so-called 3D-EBSD tomography). In both two cases, successive layers of studying object are eroded with the help of ion beam, and sequentially acquired SEM or EBSD images are utilized to reconstruct material volume. Because of different uncontrolled disruptions, drifts are generally presented during the acquisition of FIB-SEM tomography. We have developed thus a live drift correction procedure to keep automatically the region of interest (ROI) in the field of view. For the reconstruction of investigated volume, a highly precise post-mortem alignment is desired. Current methods using the cross-correlation, expected to be robust as this digital technique, show severe limitations as it is difficult, even impossible sometimes to trust an absolute reference. This has been demonstrated by specially-prepared experiments; we suggest therefore two alternative methods, which allow good-quality alignment and lie respectively on obtaining the surface topography by a stereoscopic approach, independent of the acquisition of FIB-SEM tomography, and realisation of a crossed ‘hole’ thanks to the ion beam. As for 3D-EBSD tomography, technical problems, linked to the driving the ion beam for accurate machining and correct geometrical repositioning of the sample between milling and EBSD position, lead to an important limitation of spatial resolution in commercial softwares (~ 50 nm)3. Moreover, 3D EBSD suffers from theoretical limits (large electron-solid interaction volume for EBSD and FIB milling effects), and seems so fastidious because of very long time to implement. A new approach, coupling SEM imaging of good resolution (a few nanometres for X and Y directions) at low SEM voltage and crystal orientation mapping with EBSD at high SEM voltage, is proposed. This method requested the development of computer scripts, which allow to drive the milling of FIB, the acquisition of SEM images and EBSD maps. The interest and feasibility of our approaches are demonstrated by a concrete case (nickel super-alloy). Finally, as regards crystal orientation mapping, an alternative way to EBSD has been tested; which works on the influence of channelling effects (ions or electrons) on the imaging contrast of secondary electrons. This new method correlates the simulations with the intensity variation of each grain within an experimental image series obtained by tilting and/or rotating the sample under the primary beam. This routine is applied again on a real case (polycrystal TiN), and shows a max misorientation of about 4° for Euler angles, compared to an EBSD map. The application perspectives of this approach, potentially faster than EBSD, are also evoked
Llobet, Sixto Jordi. "Focused ion beam implantation as a tool for the fabrication of nano electromechanical devices." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/384934.
Повний текст джерелаThe thesis entitled “Focused ion beam implantation as a tool for the fabrication of nano electromechanical devices” aboard the challenge of the fabrication of nanometric resonators from a new approach based on ion implantation by a focused ion beam (FIB) . This new method allows the fabrication of functional suspended nanodevices, from the electrical and mechanical point of view, without using any resist. This method is i) fast and simple, where only three steps are needed; ii) flexible, it is feasible the definition of structures of different shape; iii) high resolution, it is demonstrated the fabrication of 4 μm length and 10 nm diameter suspended devices; iv) reproducible and v) CMOS compatible. The starting point is a silicon or SOI (silicon – silicon dioxide – silicon) chip. The fabrication approach starts with a FIB implantation process where the structures and the electrical connections of the device are defined. The second step consists on silicon wet etching, where silicon that is not protected by the FIB implantation is etched, allowing the release of the devices. The defined structures are made of amorphous silicon, they contains gallium and they are not functional electrically (ρ ~1 Ω·m). The last step consists on diffusive boron doping at high temperature (up to 1000ºC) in a boron environment, where it is promoted the recrystallization of silicon forming nanocrystals, the boron doping (p type) of silicon and the removal of gallium. In this last step at high temperature the structures are not oxidized obtaining electrically functional devices (ρ ~10-4 Ω·m). The principal results can be classified in three areas: Investigation of the effect of gallium ion implantation onto silicon from the process and nanoelectromechanical material properties point of view. In this work the material structure in the different fabrication steps has been characterized, as well as the electrical and electromechanical properties of the final devices obtained by the described method. Development and optimization of the fabrication process, especially controlling the dimensions and the combination with other fabrication processes. The work done in the optimization of the different fabrication parameters are shown, from the tuning of the ion dosage to the etching selectivity. It is possible to stablish design strategies to control and minimize the under-etching effects onto silicon, as well as to avoid the collapse of long structures, that are the result of the superficial sticking produced during the wet etching processes, by the fabrication of sustaining posts. That method permits to obtain customized devices. It is a versatile prototyping method that allows the fabrication of small batches of devices of nanometric dimensions that can be employed for the scientific and academic experimentation. Investigation of the electronical, mechanical and electromechanical properties of the devices, specifically suspended silicon nanowires that can be employed as high frequency mechanical resonators or single hole transistors. We fabricated resonators of different geometries for the study and demonstration of the relation between the geometrical symmetry/asymmetry of the devices and the piezoresistive signal measured during the electromechanical transduction. We investigated and fabricated ultra-thin field effect transistors (10 ~ 15 nm) and suspended transistors that exhibits Coulomb blockade electrical characteristics at low temperature thanks to the nanocrystals that are grown during the high temperature fabrication step.
Youssef, Amanda. "Three-dimensional defect characterization : focused ion beam tomography applied to tin sulfide thin films." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92112.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 81-86).
Porosity is postulated to be one of the reasons for the low efficiency of tin sulfide-based devices. This work is a preliminary investigation of the effects of two film growth parameters deposition rate and substrate temperature - on porosity. We employ the focused ion beam tomography technique to characterize and quantify porosity in tin sulfide thin films. We then generate 3D reconstructions of pores inside milled volumes from the films and quantify pore volumes. To explain the results, we employ nucleation theory and develop two different models: (a) a thermodynamic model that assumes pores form primarily from an effect known as "self-shadowing," whereby growth-rate anisotropy results in some grains that grow faster than their neighbors, and (b) a kinetic model that assumes a diffusion-driven process of void formation. We show that both models qualitatively support the experimental results, providing insight into process-structure relations that may improve film quality during growth.
by Amanda Youssef.
S.M.
Llobet, Sixto Josep. "Focused ion beam implantation as a tool for the fabrication of nano electromechanical devices." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/384934.
Повний текст джерелаThe thesis entitled “Focused ion beam implantation as a tool for the fabrication of nano electromechanical devices” aboard the challenge of the fabrication of nanometric resonators from a new approach based on ion implantation by a focused ion beam (FIB) . This new method allows the fabrication of functional suspended nanodevices, from the electrical and mechanical point of view, without using any resist. This method is i) fast and simple, where only three steps are needed; ii) flexible, it is feasible the definition of structures of different shape; iii) high resolution, it is demonstrated the fabrication of 4 μm length and 10 nm diameter suspended devices; iv) reproducible and v) CMOS compatible. The starting point is a silicon or SOI (silicon – silicon dioxide – silicon) chip. The fabrication approach starts with a FIB implantation process where the structures and the electrical connections of the device are defined. The second step consists on silicon wet etching, where silicon that is not protected by the FIB implantation is etched, allowing the release of the devices. The defined structures are made of amorphous silicon, they contains gallium and they are not functional electrically (ρ ~1 Ω·m). The last step consists on diffusive boron doping at high temperature (up to 1000ºC) in a boron environment, where it is promoted the recrystallization of silicon forming nanocrystals, the boron doping (p type) of silicon and the removal of gallium. In this last step at high temperature the structures are not oxidized obtaining electrically functional devices (ρ ~10-4 Ω·m). The principal results can be classified in three areas: Investigation of the effect of gallium ion implantation onto silicon from the process and nanoelectromechanical material properties point of view. In this work the material structure in the different fabrication steps has been characterized, as well as the electrical and electromechanical properties of the final devices obtained by the described method. Development and optimization of the fabrication process, especially controlling the dimensions and the combination with other fabrication processes. The work done in the optimization of the different fabrication parameters are shown, from the tuning of the ion dosage to the etching selectivity. It is possible to stablish design strategies to control and minimize the under-etching effects onto silicon, as well as to avoid the collapse of long structures, that are the result of the superficial sticking produced during the wet etching processes, by the fabrication of sustaining posts. That method permits to obtain customized devices. It is a versatile prototyping method that allows the fabrication of small batches of devices of nanometric dimensions that can be employed for the scientific and academic experimentation. Investigation of the electronical, mechanical and electromechanical properties of the devices, specifically suspended silicon nanowires that can be employed as high frequency mechanical resonators or single hole transistors. We fabricated resonators of different geometries for the study and demonstration of the relation between the geometrical symmetry/asymmetry of the devices and the piezoresistive signal measured during the electromechanical transduction. We investigated and fabricated ultra-thin field effect transistors (10 ~ 15 nm) and suspended transistors that exhibits Coulomb blockade electrical characteristics at low temperature thanks to the nanocrystals that are grown during the high temperature fabrication step.
Rasera, Roy L. (Roy Louis). "Laser linking of metal interconnect : process considerations and failure analysis using focused ion beam milling." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/32180.
Повний текст джерелаFENG, Zhifu. "Electron Beam Lithography and Focused Ion Beam Techniques for the Development of Low Power Consumption Microelectromechanical Systems-based Chemiresistive Gas Sensors." Doctoral thesis, Università degli studi di Ferrara, 2023. https://hdl.handle.net/11392/2502108.
Повний текст джерелаGas sensors are widely used for detecting toxic gases for environmental protection, industrial monitoring, household safety, breath analysis and food deterioration. Apart from the electrochemical gas sensors, which have a short lifetime, and optical gas sensors with large volume size with high cost, semiconductor metal oxide (SMO) gas sensors as one of the chemiresistive type gas sensors are now developing fast owing to its low production cost, stable physical properties and chemical versatility. However, regarding the high operational temperature of SMO gas sensors, reduction of power consumption is extremely important for its application in smartphones and other portable devices. For this purpose, miniaturization of SMO gas sensor devices, primarily for the hotplate part acting as mechanical support of the sensing material and heater/electrode part, is an effective way to improve the power efficiency. Microelectromechanical systems (MEMS) offer an opportunity to achieve such goal. This dissertation addressed to miniaturization of the hotplate, was focused on hotplate fabrication by using Electron Beam Lithography (EBL) and Focused Ion Beam (FIB). Then two different approaches were studied and used at Bruno Kessler Foundation facilities to microfabricate the hotplates. First method combined EBL and FIB techniques to define the layout. EBL was used to exposure the micro-level size electrode part (or pad part), and FIB was used to mill the heater circuit part with fine and dense structure. The patterned hotplate structure was characterized by Scanning Electron Microscope (SEM), and the milling result was analyzed by Secondary-ion Mass Spectrometry (SIMS). By studying these results, the optimized parameters for EBL and FIB were selected. The second method used two-step EBL exposure. Low energy of electron beam with low dose and large writing field for the electrode part exposure and high energy of electron beam with high dose and small writing field for the dense heater circuit patterning. After these hotplates were fabricated, their electrical and thermal properties were experimentally evaluated. Subsequently, chemiresistive sensors based on the developed hotplates were developed. In particular, n-type sensing material ZnO nano film was deposited on MHP2 and NHP1 by magnetron sputtering technique. SEM revealed the nano size of ZnO particle, and the calcination condition effect on the size of ZnO. ZnO crystal structure was characterized by X-ray Powder Diffraction (XRD), and X-Ray Photoelectron Spectroscopy (XPS) proved the atom ratio of Zn and O. ZnO nanofilm did not show strong response to humidity, but humidity could decrease the response toward NO2, and increase the response toward ethanol. Thick films of SnO2 highly doped by antimony with concentration of 10 wt% (ATO1) and 15wt% (ATO2) were drop coated on MHP1. These materials were characterized by SEM, XRD and XPS. It suggested that antimony doping modified the morphology of SnO2 powder by preventing the growth of powder particles. The results of the XPS experiment demonstrated that the concentration of antimony was higher on the surface of SnO2 than its inside. It was found that ATO sensors led to a particularly high selectivity and sensitivity to NO2 when compared to the other gases at 400 °C in dry air. Additionally, the sensing response of ATO1 and ATO2 was only moderately affected by humidity, which made them ideal candidates to detect NO2 in the actual atmosphere.
Silva, Marcelo Macchi da. "Micro e nanofabricação (fabricação de contatos eletricos) por feixe de ions focalizados." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259243.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: A nanotecnologia e uma área nova e promissora que englobam muitas disciplinas de ciência e engenharia. Seu rápido crescimento nas ultimas duas décadas é devido ao crescimento simultâneo na fabricação e caracterização de materiais em escala nanométrica. O objetivo deste trabalho é desenvolver uma técnica de processo híbrido para a fabricação de micro e nanocontatos assim como sua caracterização elétrica. Esse processo híbrido combina a fotolitografia seguida da técnica de lift-off e a deposição de platina por FIB. Para determinar a resistividade da platina depositada por FIB (Focuded Ion Beam), foram fabricas estruturas quadradas variando sua espessura de 5 nm - 100 nm e sua área 150 µm 150 µm e 20 µm x 20 µm. Resistores com comprimento de 30 µm variando sua área de secção (50 nm x 50 nm - 1 µm x 1 µm) foram fabricados a fim de uma melhor na caracterização do processo de deposição do filme de Pt assim como sua caracterização elétrica. As medidas elétricas foram realizadas na estação Keythley 4200 SCS, onde foi utilizado o método de quatro pontas nas estruturas quadradas para a caracterização da resistividade. Nos resistores utilizamos a configuração de dois terminais para a caracterização de resistência dos nanocontatos.
Abstract: Nanoscale science and technology is a young and burgeoning field that encompasses nearly every discipline of science and engineering, the rapid growth of the field in the past decades has been enable by the sustained advances in the fabrication and characterization of materials. This work presents the hybrid process for fabrication of micro and nanocontacts, this process include the lift - off technique and platinum deposited by FIB. For measurements, two types of test structures were fabricated: (i) 150 x 150 µm and 20 x 20 µm squares with thickness of 5, 10, 30 and 100 nm, and (ii) 30 µm long resistors with variable cross - section (50 nm x 50 nm to 1 µm x 1 µm). The Pt film resistivity has been measured by a four points probe method.
Mestrado
Eletrônica, Microeletrônica e Optoeletrônica
Mestre em Engenharia Elétrica
Drǎghici, Mihai. "In-plane gate transistors fabricated by focused ion beam implantation in negative and positive pattern definition." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=983711526.
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