Download or read book Growth and Characterization of Silicon Carbide Thin Films and Nanowires written by Lunet Estefany Luna and published by . This book was released on 2016 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide (SiC) based electronics and sensors hold promise for pushing past the limits of current technology to achieve small, durable devices that can function in high-temperature, high-voltage, corrosive, and biological environments. SiC is an ideal material for such conditions due to its high mechanical strength, excellent chemical stability, and its biocompatibility. Consequently, SiC thin films and nanowires have attracted interest in applications such as micro- and nano-electromechanical systems, biological sensors, field emission cathodes, and energy storage devices. In terms of high-temperature microdevices, maintaining low-resistance electrical contact between metal and SiC remains a challenge. Although SiC itself maintains structural and electrical stability at high temperatures, the metallization schemes on SiC can suffer from silicide formation and oxidation when exposed to air. The second chapter presents efforts to develop stable metallization schemes to SiC. A stack consisting of Ni-induced solid-state graphitization of SiC and an atomic layer deposited layer of alumina is shown to yield low contact resistivity of Pt/Ti to polycrystalline n-type 3C-SiC films that is stable in air at 450 oC for 500 hours. The subsequent chapters focus on the growth and structural characterization of SiC nanowires. In addition to its structural stability in harsh-environments, there is interest in controlling SiC crystal structure or polytype formation. Over 200 different polytypes have been reported for SiC, with the most common being 3C, 4H, and 2H. In terms of SiC nanowire growth, the 3C or cubic phase is the most prevalent. However, as the stacking fault energy for SiC is on the order of a few meV, it is common to have a high density of stacking faults within a given SiC crystal structure. Thus, to enable reliable performance of SiC nanowires, a growth method that can promote a specific polytype or reduce stacking faults is of importance. Ni-catalyzed chemical vapor deposition method is employed for the growth of the nanowires. The effects of substrate structure and quality as well as the various growth parameters such as temperature, pressure, and post-deposition annealing are investigated. Most significant has been the growth and characterization of vertically aligned hexagonal phase (or 4H-like) SiC nanowires grown on commercially available 4H-SiC (0001). The studies presented in this thesis tackle issues in SiC metallization and nanowire growth in efforts to expand the versatility of SiC as a material platform for novel devices.

Download or read book Growth and Characterization of Beta silicon Carbide Thin Films written by Bagher Bahavar and published by . This book was released on 1993 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Growth and Characterization of Beta Silicon Carbide beta Sic Thin Films by Chemical Vapor Deposition in a Low Pressure Vertical Reactor written by Kenneth George Irvine and published by . This book was released on 1992 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Growth and Characterization of Beta Silicon Carbide Sic Thin Films by Chemical Vapor Deposition in a Low Pressure Vertical Reactor written by Kenneth George Irvine and published by . This book was released on 1992 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Growth and Characterization of Silicon Carbide Thin Films Using a Nontraditional Hollow Cathode Sputtering Technique written by James Huguenin-Love and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Amorphous Silicon Carbide Thin Films written by Mariana Amorim Fraga and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon carbide (SiC) has been described as a suitable semiconductor material to use in MEMS and electronic devices for harsh environments. In recent years, many developments in SiC technology as bulk growth, materials processing, electronic devices and sensors have been shown. Moreover, some studies show the synthesis, characterisation and processing of crystalline SiC films. However, few works have investigated the potential of amorphous silicon carbide (a-SiC) thin films for sensors applications. This book presents fundamentals of amorphous silicon carbide thin films and their applications in piezoresistive sensors for high temperature applications.

Download or read book Growth and Characterization of Polycrystalline Silicon and Microcrystalline Silicon Carbide Thin Films Using ECR PECVD written by Bryan Kent Oliver and published by . This book was released on 1999 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the other hand, with He dilution at 15 mTorr the percent crystallinity obtained was also 86%, with decreasing crystallinity at lower pressures. We found that a dilution consisting of a 50%-50% mixture of H2-He, which allows a high ion bombardment deposition from the helium that is also benefited by the hydrogen etching effect, did not compromise the quality of the films. This plasma selection produced about 84% crystalline films, independent of the pressure setting. X-ray diffraction reveals the dominant crystal textures are 111 and 220 orientations, with 220 preferential growth at higher deposition pressures. The CH4/SiH4 flow ratio was found critical to the formation of microcrystalline SiC.

Download or read book Silicon Carbide Nanostructures written by Jiyang Fan and published by Springer. This book was released on 2014-07-26 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together the most up-to-date information on the fabrication techniques, properties, and potential applications of low dimensional silicon carbide (SiC) nanostructures such as nanocrystallites, nanowires, nanotubes, and nanostructured films. It also summarizes the tremendous achievements acquired during the past three decades involving structural, electronic, and optical properties of bulk silicon carbide crystals. SiC nanostructures exhibit a range of fascinating and industrially important properties, such as diverse polytypes, stability of interband and defect-related green to blue luminescence, inertness to chemical surroundings, and good biocompatibility. These properties have generated an increasing interest in the materials, which have great potential in a variety of applications across the fields of nanoelectronics, optoelectronics, electron field emission, sensing, quantum information, energy conversion and storage, biomedical engineering, and medicine. SiC is also a most promising substitute for silicon in high power, high temperature, and high frequency microelectronic devices. Recent breakthrough pertaining to the synthesis of ultra-high quality SiC single-crystals will bring the materials closer to real applications. Silicon Carbide Nanostructures: Fabrication, Structure, and Properties provides a unique reference book for researchers and graduate students in this emerging field. It is intended for materials scientists, physicists, chemists, and engineers in microelectronics, optoelectronics, and biomedical engineering.

Download or read book Silicon Carbide written by Wolfgang J. Choyke and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the 1997 publication of "Silicon Carbide - A Review of Fundamental Questions and Applications to Current Device Technology" edited by Choyke, et al., there has been impressive progress in both the fundamental and developmental aspects of the SiC field. So there is a growing need to update the scientific community on the important events in research and development since then. The editors have again gathered an outstanding team of the world's leading SiC researchers and design engineers to write on the most recent developments in SiC.

Download or read book Growth and Characterization of Silicon Carbide on AIN Si written by John H. Goldsmith and published by . This book was released on 2008 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Epitaxial silicon carbide (SiC) was grown using chemical vapor deposition (CVD) on silicon substrates with Aluminum Nitride (AIN) buffer layers. Subsequent films where characterized by Raman Spectroscopy, Scanning Electron microscopy, Atomic Force microscopy, and X-ray diffraction. There is a large lattice mismatch between SiC and silicon, by introducing an AIN buffer layer, which has a close lattice match to SiC, the strain on the film is reduced and hence the density of defects is reduced. Trimethylsilane, an relatively inert alternative to silane, was used as the precursor providing both the required silicon and carbon atoms.

Download or read book Crystal Growth and Characterization of Silicon Carbide and Aluminum Nitride Films written by Zhenjiang Yu and published by . This book was released on 1993 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Silicon Carbide One dimensional Nanostructures written by Laurence Latu-Romain and published by John Wiley & Sons. This book was released on 2015-02-23 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dedicated to SiC-based 1D nanostructures, this book explains the properties and different growth methods of these nanostructures. It details carburization of silicon nanowires, a growth process for obtaining original Si-SiC core-shell nanowires and SiC nanotubes of high crystalline quality, thanks to the control of the siliconout-diffusion. The potential applications of these particular nano-objects is also discussed, with regards to their eventual integration in biology, energy and electronics.

Download or read book The Growth and Characterization of Silicon Nanowires written by Parul Sharma and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The growth and characterization of silicon nanowires carbon nanotubes for heterojunctions written by Parul Sharma and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanostructured Thin Films and Coatings written by Sam Zhang and published by CRC Press. This book was released on 2010-06-18 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Authored by leading experts from around the world, the three-volume Handbook of Nanostructured Thin Films and Coatings gives scientific researchers and product engineers a resource as dynamic and flexible as the field itself. The first two volumes cover the latest research and application of the mechanical and functional properties of thin films an

Download or read book Silicon and Silicon Carbide Nanowires written by John Paul Alper and published by . This book was released on 2014 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: For applications in mobile and remote sensing platforms, microsupercapacitors are attractive energy storage devices due to their robust lifetimes and high specific power capacity. Utilization of green electrolytes in these devices reduces environmental impact and simplifies packaging by avoiding the stringent oxygen and moisture free conditions required for organic and ionic liquid based electrolytes. Porous silicon nanowire based microsupercapacitor electrode materials are promising for on chip applications using an environmentally benign aqueous electrolyte, 1 M KCl, however they are prone to oxidation. A silicon carbide coating was found to mitigate this issue. The fabrication techniques, involving low-temperature electroless etching of silicon, are compatible with current integrated circuit processing methods and may be readily integrated at the micro device level. The electrode materials are in good electrical contact with the underlying substrate and require no additional current collector. The base porous silicon nanowires are coated with a thin silicon carbide passivation layer by low pressure chemical vapor deposition. The demonstrated capacitance of the electrode materials, ~1700 [mu]F/cm2 projected area, is comparable to other carbon based microsupercapacitor electrodes, remains stable over many charge/discharge cycles, and maintains capacitive behavior over a wide range of charge/discharge rates. An improved passivation method for the porous silicon nanowires has also been developed. The selective coating procedure deposits an ultra-thin (~ 1-3 nm) carbon sheath over the nanowires and passivates them. The ultra-thin nature of the coating enables solvent access to the pore area and hence a large improvement of active specific surface over the SiC coated PSiNWs discussed above. The electrochemical performance of these coated nanowires is characterized in both an aqueous electrolyte and an ionic liquid electrolyte. Specific capacitance values reaching 325 mF cm 2 are achieved in ionic liquid, and calculations indicate that the theoretical maximum capacitance of the pristine wires is reached. TEM studies confirm the coating thickness and its conformality. Raman spectroscopy indicates that the carbon in the coating is mainly sp2 hybridized, with corresponding high conductivity. At the time of writing, these materials represent the largest specific energy microsupercapacitor electrode published. A test device is prepared and demonstrated powering an LED. The testing results of silicon carbide (SiC) nanowires (NW) as an electrode material for micro-supercapacitors is described. SiC NWs are grown on a SiC thin film coated with a thin Ni catalyst layer via chemical vapor deposition. A specific capacitance of ~240 μF cm-2 is demonstrated. Charge-discharge studies demonstrate the SiC nanowires exhibit exceptional stability, with 95% capacitance retention after 2×105 charge/discharge cycles in an environmentally benign, aqueous electrolyte. Doping of the nanowires with nitrogen through the addition of 5 at% ammonia to the precursor gas flow rate improves the conductivity of the nanowire films by over an order of magnitude leading to increased power capabilities. A method to transfer silicon and silicon carbide nanowire arrays to arbitrary substrates while maintaining electrical contact through the entire array is elucidated. The nanowires are grown on graphene sheets on SiO2 coupons. The graphene acts as both the flexible material for maintaining structural continuity and electrical contact through the array during transfer. The SiO2 acts as the sacrificial growth substrate which is etched after growth in order to release the nanowire/graphene hybrid. The nanowire/graphene hybrids are structurally characterized by XRD and electron microscopy. Good electrical contact is confirmed through testing of the SiCNW/graphene hybrids as supercapacitor electrode materials in an aqueous electrolyte. The specific capacitance, ~340 mF cm-2, is similar to SiCNW arrays grown on oxide while the electrical conductivity is improved and cycling stability tests show less than a 1% decrease in capacitance after 10,000 cycles.

Download or read book Characterization of Planar Defects in Silicon Carbide Nanowires written by Monika Katarzyna Wieligor and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Stacking faults and twins were identifying in SiC nanowires produced according three different synthesis methods. By direct observation of high resolution TEM images, analysis of Raman spectra, and from X-ray diffraction results we concluded that planar defects were present in all specimens, regardless the synthesis method. The study of TEM images revealed that concentration of defects was not uniform. The amount of stacking faults and twins varied between the samples, and seems to be dependent on the size of nanowires. Concentration of twins appeared to be highest in nanowires obtained from raw carbon blacks of small diameters. The quantitative analysis of concentration of defects was not conducted because Raman and conventional X-ray cannot discern stacking faults and twins. Therefore, the estimation of concentration of planar defects was based on the examination of TEM images. The application of two TEM modes, bright field and dark field, let to deduce that twins played a dominant role in observed defects. A minimum surface energy and strain energy argument was proposed to explain the formation of twins in the SiC nanowires. The high pressure measurements in DAC were performed and the results validated the core-shell model. The application of new carbon precursor revealed with new, highly efficient method of synthesis of SiC nanowires. We proved that it is possible to produce low-cost, catalyst-free, and high-yield SiC nanowires of 10 nm diameter and narrow size distribution. Morphology of the nanowires depended on carbon precursor used. That technique was described in details in Chapter IV. The model of typical nanowire, composed of crystalline SiC core, coated by thin, 2 nm amorphous SiC layer, was presented. After analysis of produced SiC nanowires we were able to construct the possible model of growth mechanism, and explain the differences in dimensions and morphology for nanowires, obtained from graphitized and not graphitized carbon blacks precursors. We deduced that vapor-solid growth mechanism is more plausible in nanowires synthesis from carbon black, than the vapor-liquid-solid mechanism"--Abstract.