98 research outputs found
A Comparison between Thin-Film Transistors Deposited by Hot-Wire Chemical Vapor Deposition and PECVD
The effect of new growth techniques on the mobility and stability of amorphous silicon (a-Si:H) thin film transistors (TFTs) has been studied. It was suggested that the key parameter controlling the field-effect mobility and stability is the intrinsic stress in the a-Si:H layer. Amorphous and microcrystalline silicon films were deposited by radiofrequency plasma enhanced chemical vapor deposition (RF-PECVD) and hot-wire chemical vapor deposition (HW-CVD) at 100 ºC and 25 ºC. Structural properties of these films were measured by Raman Spectroscopy. Electronic properties were measured by dark conductivity, σd, and photoconductivity, σph. For amorphous silicon films deposited by RF-PECVD on PET, photosensitivity's of >105 were obtained at both 100 º C and 25 ºC. For amorphous silicon films deposited by HW-CVD, a photosensitivity of > 105 was obtained at 100 ºC. Microcrystalline silicon films deposited by HW-CVD at 95% hydrogen dilution show σph~ 10-4 Ω-1cm-1, while maintaining a photosensitivity of ~102 at both 100 ºC and 25 ºC. Microcrystalline silicon films with a large crystalline fraction (> 50%) can be deposited by HW-CVD all the way down to room temperature
The Role of SiO2 Gas in the Operation of Anti-Corrosion Coating Produced by PVD
This study examined theSiO2 gas present in the coatings used in corrosion industry.These layers have been created by physical vapor deposition (PVD), with an appropriate performance. Sublimation of SiO2is used to protect PVD aluminum flakes from water corrosionand to generate highly porous SiO2 flakes with holes in the nanometer range. SiOx/Al/SiOx sandwiches were made as well as Ag loaded porous SiO2 as antimicrobial filler
Characterization of the SiO2 film deposited by using plasma enhanced chemical vapor deposition (PECVD) with TEOS/N2/O2
The purpose of this study was to examine how certain parameters like temperature, pressure, and gas composition affect the characteristics of SiO2 film by Plasma Enhanced Chemical Vapor Deposition (PECVD). We used of low temperature and an inductively coupled plasma (ICP) for various with gas mixtures of TEOS/N2/O2 at a given RF power and dc bias voltage. For the gas mixture with 40 sccm of N2 in TEOS, 100 standard cubic centimeters per minute (sccm) of N2, and 500 sccm of O2, transparent and scratch-resistant SiO2 could be deposited with a deposition rate of 30 nm/min when RF power of 500 W and a dc-bias voltage of 350V were applied. The characteristics of the deposited SiO2, such as the composition, the binding energy, etc. were compared with the SiO2 deposited by using thermal CVD and evaporation. It was found that the SiO2 deposited by PECVD with TEOS/N2/O2 exhibited properties typical of SiO2 deposited applying thermal CVD and evaporation. The surface roughness of the 100 nm-thick SiO2 deposited by PECVD was similar to that of the substrate
Properties of Silicon Dioxide Film Deposited By PECVD at Low Temperature/Pressure
conventional plasma enhanced chemical vapor deposition (PECVD) at low temperature/pressure with silane (SiH4) and nitrous oxide (N2O) as precursor gases. The ellipsometer and stress measurement system were used to test the thickness and refractive index uniformity of the SiO2 film fabricated. The effects of radio frequency (RF) power chamber pressure and N2O/SiH4 flow ratio on the properties of SiO2 film were studied. The results show that the refractive index of SiO2 film is mainly determined by N2O/SiH4 flow ratio .Moreover, the formation of SiO2 thin films is confirmed by Fourier transform infrared (FTIR) spectroscopy. The thickness and refractive indices of the films measured by ellipsometry C-V measurement show that the electrical properties are directly related to process parameters and Si/SiO2 interface. The MIS structures were also fabricated from optimized SiO2 layer to study C-V measurement and to estimate interface, oxide and effective border traps density. The deposited SiO2 films have good uniformity, compact structure, high deposition rate, low deposition temperature and controllable stress, which can be widely, used in semiconductor devices. http://dx.doi.org/10.5937/metmateng1402089
The role of PECVD hard coatings on the performance of industrial tools
The advantages of the application of hard coatings, which are well knownfor cutting tools, are to a much lesser extent explored for casting, extrusion, molding and forming tools. Increasing the lifetime of these tools is an important task in surface engineering because of complex loading conditionsand often complicated tool geometry. The plasma-enhanced chemical vapor deposition (PECVD) technique is well suited to deposit hard coatings onto large dies and moulds. The aim of this study was to discuss deposition processes suitable for coating of the often large three-dimensional molds and dies used in metal forming. Furthermore, results obtained using different hard coatings in industrial applications for several case studies like aluminum pressure die-casting; plastics injection molding and sheet metal forming are presented and discussed. For best coating performance, a careful optimization of both substrate pretreatment and coating deposition is necessary. The plasma-enhanced chemical vapor deposition (PECVD) technique shows advantages for these applications because of the high flexibility in pre-treatment using chemical etching and plasma-nitriding, because of its ability to coat large complexly shaped tools and because of the possibility of deposition of low-chlorine containing low-friction coatings. http://dx.doi.org/10.5937/metmateng1401015
Investigating Deep Neural Network Architecture and Feature Extraction Designs for Sensor-based Human Activity Recognition
The extensive ubiquitous availability of sensors in smart devices and the
Internet of Things (IoT) has opened up the possibilities for implementing
sensor-based activity recognition. As opposed to traditional sensor time-series
processing and hand-engineered feature extraction, in light of deep learning's
proven effectiveness across various domains, numerous deep methods have been
explored to tackle the challenges in activity recognition, outperforming the
traditional signal processing and traditional machine learning approaches. In
this work, by performing extensive experimental studies on two human activity
recognition datasets, we investigate the performance of common deep learning
and machine learning approaches as well as different training mechanisms (such
as contrastive learning), and various feature representations extracted from
the sensor time-series data and measure their effectiveness for the human
activity recognition task.Comment: Seventh International Conference on Internet of Things and
Applications (IoT 2023
The Role of SiO2 Gas in the Operation of Anti-Corrosion Coating Produced by PVD
This study examined theSiO2 gas present in the coatings used in corrosion industry.These layers have been created by physical vapor deposition (PVD), with an appropriate performance. Sublimation of SiO2is used to protect PVD aluminum flakes from water corrosionand to generate highly porous SiO2 flakes with holes in the nanometer range. SiOx/Al/SiOx sandwiches were made as well as Ag loaded porous SiO2 as antimicrobial filler
A Comparison between Thin-Film Transistors Deposited by Hot-Wire Chemical Vapor Deposition and PECVD
The effect of new growth techniques on the mobility and stability of amorphous silicon (a-Si:H) thin film transistors (TFTs) has been studied. It was suggested that the key parameter controlling the field-effect mobility and stability is the intrinsic stress in the a-Si:H layer. Amorphous and microcrystalline silicon films were deposited by radiofrequency plasma enhanced chemical vapor deposition (RF-PECVD) and hot-wire chemical vapor deposition (HW-CVD) at 100 ºC and 25 ºC. Structural properties of these films were measured by Raman Spectroscopy. Electronic properties were measured by dark conductivity, σd, and photoconductivity, σph. For amorphous silicon films deposited by RF-PECVD on PET, photosensitivity's of >105 were obtained at both 100 º C and 25 ºC. For amorphous silicon films deposited by HW-CVD, a photosensitivity of > 105 was obtained at 100 ºC. Microcrystalline silicon films deposited by HW-CVD at 95% hydrogen dilution show σph~ 10-4 Ω-1cm-1, while maintaining a photosensitivity of ~102 at both 100 ºC and 25 ºC. Microcrystalline silicon films with a large crystalline fraction (> 50%) can be deposited by HW-CVD all the way down to room temperature
Mechanical Behavior of TiN/TiC-n Multilayer Coatings and Ti(C,N) Multicomponent Coatings Produced by PACVD
Изучены механические свойства многослойных и многокомпонентных покрытий. Многослойное нитрид-титановое/карбид-титановое (TiN/TiC-n) и многокомпонентное Ti(C,N) покрытия наносили на поверхность горячеобработанной инструментальной стали AISI H13 посредством вакуум-плазменного химического осаждения паров при воздействии импульсного постоянного тока. Исследованы микротвердость, вязкость разрушения, разрушение при износе и коэффициент трения при испытаниях на твердость по Виккерсу и износ по схеме диск шпилька . Подвергнутые износу поверхности и механизмы износа изучены с помощью оптического микроскопа. Результаты показывают, что многослойные покрытия TiN/TiC-10 имеют более низкие значения коэффициента трения (0,2) и разрушения при износе и более высокие значения вязкости разрушения (17,7 МПа м¹/²) и микротвердости (3150 VHN) по сравнению с таковыми для многокомпонентного покрытия Ti(C,N) и других исследованных многослойных покрытий.Вивчено механічні властивості багатошарових і багатокомпонентних покриттів. Багатошарове нітрид-титанове/карбід-титанове (TiN/TiC-n) і багатокомпонентне Ti(C,N) покриття наносили на поверхню гарячеобробленої інструментальної сталі AISI H13 за допомогою вакуум-плазмового хімічного осадження пара при дії імпульсного постійного струму. Досліджено мікротвердість, в язкість руйнування, руйнування при зношенні і коефіцієнт тертя при випробуваннях на твердість за Віккерсом та зношення за схемою диск шпилька . Поверхні, що зазнали зношення, та механізми зношення вивчали за допомогою оптичного мікроскопа. Результати показують, що багатошарові покриття TiN/TiC-10 мають більш низькі значення коефіцієнта тертя (0,2) і руйнування при зношенні та більш високі значення в язкості руйнування (17,7 МПа м¹/²) і мікротвердості (3150 VHN) порівняно з такими для багатокомпонентного покриття Ti(C,N) й інших досліджуваних багатошарових покриттів
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