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1.
The use of flame hydrolysis deposition (FHD) to fabricate porous silica glass soot in the B2O3-P2O5-SiO2 glass system (BPSG) is described for silica-on-silicon device applications. The deposition conditions with a Si substrate temperature (200 °C) and a flame temperature (1300–1500 °C) are appropriate to synthesize the SiO2 and P2O5-SiO2 non-crystalline glass soot. However, further investigations for the B2O3-P2O5-SiO2 glass soot are needed to obtain complete amorphous phases. The densification process of porous silica glass soot in the three systems of SiO2, P2O5-SiO2 and B2O3-P2O5-SiO2 is also described to estimate the onset of sintering temperature. The OH absorption measurements are performed to try to identify incorporation of hydroxyl contaminants in the systems of P2O5-SiO2 and B2O3-P2O5-SiO2. 相似文献
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F. Leuenberger 《Thin solid films》1974,22(3):245-253
Silicon dioxide layers deposited from the vapour phase at low temperatures are extensively applied in integrated circuit technology. Applications include doped oxide diffusion sources, protective layers and cross-over insulators in multilevel metallization systems.In this paper we show the feasibility of obtaining a SiO2Si interface whose electrical characteristics closely approach those of thermally grown SiO2Si sandwich structures. Interface state densities lying in the low 1010 cm?2 eV?1 range have been determined from quasi-static C(V) measurements. The results of excess noise measurements made on deposited gate oxide and thermally grown gate oxide MOSFETs are in reasonable agreement with the interface state density measurements. C(V) dispersion and C(V) hysteresis measurements prior to and after exposure to 107 rad of 60Co γ radiation are also presented. Potential applications of low temperature vapour-deposited oxides include the silicon on insulating substrate (SOS) technology where it is generally desirable to minimize high temperature processing steps. Other applications are in the field of impurity profile determinations using the MOS capacitor method. In these applications one desires to measure the original profile without having to deal with the additional complication of the diffusion and redistribution phenomena that occur unavoidably during high temperature thermal oxide growth. 相似文献
4.
The present state of the art of transparent, electrically conducting films, with special reference to In2O3, SnO2 and Cd2SnO4, has been reviewed. Various production techniques currently in use, and typical parameters used in the processes have been
discussed in detail. Electrical and optical properties of these films have been reported as a function of various parameters,
e.g. substrate temperature, doping, oxygen pressure, etc. Finally, the applications of these films in research and industry
have been discussed in detail. 相似文献
5.
CVD of fluorosilicate glass for ULSI applications 总被引:2,自引:0,他引:2
Interlayer dielectrics are key materials for size reduction and speed enhancement of ultra large scale integrated devices. As intralevel metal spacing is reduced and lower capacitance is required, the choices for inorganic dielectrics are limited, Fluorosilicate glass is a material that is being considered to meet these requirements because it has shown the ability to extend SiO2 chemical vapor deposition processing. Fluorine addition in a conventional glass improves gap fill while simultaneously lowering the dielectric constant. This paper will review the progress of fluorosilicate glass processing, examine the reliability of these materials, and discuss the role of fluorine in increasing gap fill and lowering the dielectric constant of standard SiO2 films. 相似文献
6.
G. P. Tartaro S. D'Amato A. Itro G. Carotenuto A. Gallo L. Nicolais 《Journal of materials science. Materials in medicine》1996,7(7):431-438
The clinical use of glass ionomers is well established in the odontological field. In particular; (i) high biocompatibility (unincreased macrophages activity), and consquently no inflammation in post-operative course; (ii) total non-toxicity of components; (iii) absence of mutagenic consequence on osteoblasts; (iv) dimensional stability and absence of macroscopic changes after very long implantation times; (v) stability to water and biological compounds, make these materials attractive for further clinical applications. The high adhesion both to metallic or ceramic surfaces and bone tissue makes this materials excellently usable for the adjustment of bone defects. This goal necessitates suitable knowledge of the mechanical, chemical, physical and biological properties of commercial materials so that the most suitable product can be identified. The characterization of representative products of each of the principal classes of glass ionomers material is reported. 相似文献
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In the new emerging markets of flat panel display, photovoltaic and optical coating applications, the introduction of cylindrical rotating magnetron technology can accommodate the needs for faster, better and cheaper coating processes. Recent developments of hardware (compact end blocks, etc.) and target materials for rotatable magnetron technology offer a total solution to the innovative thin film applications. 相似文献
9.
Guocheng Wang Zufu Lu Xuanyong Liu Xiaming Zhou Chuanxian Ding Hala Zreiqat 《Journal of the Royal Society Interface》2011,8(61):1192-1203
Glass–ceramics have attracted much attention in the biomedical field, as they provide great possibilities to manipulate their properties by post-treatments, including strength, degradation rate and coefficient of thermal expansion. In this work, hardystonite (HT; Ca2ZnSi2O7) and sphene (SP; CaTiSiO5) glass–ceramic coatings with nanostructures were prepared by a plasma spray technique using conventional powders. The bonding strength and Vickers hardness for HT and SP coatings are higher than the reported values for plasma-sprayed hydroxyapatite coatings. Both types of coatings release bioactive calcium (Ca) and silicon (Si) ions into the surrounding environment. Mineralization test in cell-free culture medium showed that many mushroom-like Ca and phosphorus compounds formed on the HT coatings after 5 h, suggesting its high acellular mineralization ability. Primary human osteoblasts attach, spread and proliferate well on both types of coatings. Higher proliferation rate was observed on the HT coatings compared with the SP coatings and uncoated Ti-6Al-4V alloy, probably due to the zinc ions released from the HT coatings. Higher expression levels of Runx2, osteopontin and type I collagen were observed on both types of coatings compared with Ti-6Al-4V alloy, possibly due to the Ca and Si released from the coatings. Results of this study point to the potential use of HT and SP coatings for orthopaedic applications. 相似文献
10.
There is an accepted clinical requirement for a luting cement that can be command set upon satisfactory placement of an orthodontic
appliance onto dentition. This work evaluates the suitability of ultrasound, imparted from a dental scaler, as a potential
mechanism for achieving this. The net setting times and subsequent compressive strengths of a range of commercial and experimental
glass polyalkenoate cements (GPCs) were evaluated, using modified ISO 9917 methods, when set both chemically and by ultrasound.
The ultrasound was applied to the GPC through an orthodontic brace. It was possible to command set GPCs by the application
of five to ten seconds of ultrasound; the exact time required being dependent upon the composition of the GPC in question.
The compressive strengths of these cements can be improved by around 90% with the command set when the optimum PAA molecular
weight and tartaric acid content is employed. 相似文献
11.
The properties of a glass epoxy have been studied following heat treatment under vacuum at 150°C. Little change in physical and electrical properties occurs but the outgassing rate of the material is reduced by an order of magnitude. 相似文献
12.
M. Koopman K. K. Chawla W. Ricci K. Carlisle G. M. Gladsyz M. Lalor M. L. Jones K. Kerr M. P. George G. Gouadec Aurélie Tournié 《Journal of Materials Science》2009,44(6):1435-1441
Functional titania coatings on glass microballoons (GMBs) and cenospheres have a broad range of potential environmental applications,
primarily in purification of drinking water and treatment of industrial wastewater. The heterogeneous photocatalytic capabilities
of titania films and particles have been extensively examined in the literature as effective alternatives to current technologies.
Although the chemistry of titania films for photocatalysis has been studied, titania-coated GMBs have not yet been extensively
considered and the materials science aspects of the titania-GMB and titania-cenosphere systems have not been addressed. We
have examined the microstructure, morphology, and mechanical properties of titania coatings on both cenospheres and commercially
produced GMBs. Scanning electron microscopy was used to examine coating coverage and defects. Energy dispersive X-ray spectroscopy
and Raman spectroscopy were used for element and phase identification, respectively. Hardness and modulus measurements of
the titania coatings and the GMB and cenosphere materials were done by nanoindentation. Additionally, the photocatalytic activity
of the titania-coated GMB system was tested on Procion Red dye using two different types of mixing, a magnetic stirrer and
an aeration bubbler apparatus. The titania coatings showed good coverage and retention except in the case of magnetic stirring,
where significant coating loss was observed. 相似文献
13.
A chemical route to graphene for device applications 总被引:5,自引:0,他引:5
Oxidation of graphite produces graphite oxide, which is dispersible in water as individual platelets. After deposition onto Si/SiO2 substrates, chemical reduction produces graphene sheets. Electrical conductivity measurements indicate a 10000-fold increase in conductivity after chemical reduction to graphene. Tapping mode atomic force microscopy measurements show one to two layer graphene steps. Electrodes patterned onto a reduced graphite oxide film demonstrate a field effect response when the gate voltage is varied from +15 to -15 V. Temperature-dependent conductivity indicates that the graphene-like sheets exhibit semiconducting behavior. 相似文献
14.
Two-dimensional(2D)selenium was synthesized successfully in 2017.Its advanced properties,including size-dependent bandgap,excellent environmental robustness,strong photoluminescence effect,anisotropic thermal conductivity,and high photoconductivity,render it and selenium-based composites a promising candidate for various device applications.These include batteries,modulators,photodetectors,and photothermal effects in medical applications.However,compared to other commonly used 2D materials,such as graphene,transition metal dichalcogenides,and black phosphorus,2D Se is much less known.Motivated by the need to overcome this lack of knowledge,this article focuses on recent progress and elucidates the crystal structure,synthesis methods,physical properties,applications,challenges,and prospects of 2D Se nanoflakes. 相似文献
15.
In recent years, bioactive materials have become important in applications such as implantation, bone regeneration, scaffold, oral implantation and antioxidant materials because of their excellent bioactivity, biocompatibility, osteoconductivity and osteoinductive properties. When exposed to simulated body fluid, bioactive glasses have the ability to bond with both hard and soft tissues through the formation of a hydroxyapatite layer. Nowadays, nanotechnology is emerging as a nascent technology in all disciplines because of its high surface-to-volume ratio and unique properties at nanoscale length. The impact of nanotechnology in biomaterials is of interest because of the enhancement in their biocompatibility and bioactivity. In this investigation, the preparation of nanobioactive glasses by using different methods (such as sol-gel, hydrothermal and sonochemical) is discussed in detail. The structural and morphological characterisation of the prepared samples was made. 相似文献
16.
Wren AW Coughlan A Hassanzadeh P Towler MR 《Journal of materials science. Materials in medicine》2012,23(5):1331-1341
Bioactive glass particles (0.42SiO2–0.15CaO–0.23Na2O–0.20ZnO) of varying size (<90 μm and 425–850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles
(PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90
to 9.12 m2/g (90 μm) and 1.09–7.71 m2/g (425–850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little
diffusion through the bulk. Antibacterial (Escherichia coli—13 mm and Staphylococcus epidermidis—12 mm) and antifungal testing (Candida albicans—7.7 mm) determined that small Ag-coated glass particles exhibited the largest inhibition zones compared to uncoated particles.
pH analysis determined an overall higher pH consider in the smaller particles, where after 24 h the large uncoated and Ag
coated particles were 8.27 and 8.74 respectively, while the smaller uncoated and Ag coated particles attained pH values of
9.63 and 9.35 respectively. 相似文献
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18.
卞伟 《制冷与空调(北京)》2012,(3):36-38,82
目前,国内的冰淇淋展示柜存在柜内储藏温度不均匀、制冷速度慢、玻璃门凝露、翅片式冷凝器易脏堵、内胆结霜过厚不易处理等问题。本文针对上述问题进行优化方案设计及匹配试验,结果表明,优化措施对降低漏冷、平衡柜内温度、防凝露除霜、平衡气压等方面有很理想的改进。 相似文献
19.
Magnus Willander Milan Friesel Qamar-ul Wahab Boris Straumal 《Journal of Materials Science: Materials in Electronics》2006,17(1):1-25
The physical and chemical properties of wide bandgap semiconductors silicon carbide and diamond make these materials an ideal
choice for device fabrication for applications in many different areas, e.g. light emitters, high temperature and high power
electronics, high power microwave devices, micro-electromechanical system (MEMS) technology, and substrates. These semiconductors
have been recognized for several decades as being suitable for these applications, but until recently the low material quality
has not allowed the fabrication of high quality devices. Silicon carbide and diamond based electronics are at different stages
of their development. An overview of the status of silicon carbide's and diamond's application for high temperature electronics
is presented.
Silicon carbide electronics is advancing from the research stage to commercial production. The most suitable and established
SiC polytype for high temperature power electronics is the hexagonal 4H polytype. The main advantages related to material
properties are: its wide bandgap, high electric field strength and high thermal conductivity. Almost all different types of
electronic devices have been successfully fabricated and characterized. The most promising devices for high temperature applications
are pn-diodes, junction field effect transistors and thyristors. MOSFET is another important candidate, but is still under
development due to some hidden problems causing low channel mobility. For microwave applications, 4H-SiC is competing with
Si and GaAs for frequency below 10 GHz and for systems requiring cooling like power amplifiers. The unavailability of high
quality defect and dislocation free SiC substrates has been slowing down the pace of transition from research and development
to production of SiC devices, but recently new method for growth of ultrahigh quality SiC, which could promote the development
of high power devices, was reported.
Diamond is the superior material for high power and high temperature electronics. Fabrication of diamond electronic devices
has reached important results, but high temperature data are still scarce. PN-junctions have been formed and investigated
up to 400 ∘C. Schottky diodes operating up to 1000 ∘C have been fabricated. BJTs have been fabricated functioning in the dc mode up to 200 ∘C. The largest advance, concerning development of devices for RF application, has been done in fabrication of different types
of FETs. For FETs with gate length 0.2 μ m frequencies fT = 24.6 GHz, fmax (MAG) = 63 GHz and fmax (U) = 80 GHz were reported. Further, capacitors and switches, working up to 450 ∘C and 650 ∘C, respectively, have also been fabricated. Low resistant thermostable resistors have been investigated up to 800 ∘C. Temperature dependence of field emission from diamond films has been measured up to 950 ∘C. However, the diamond based electronics is still regarded to be in its infancy. The prerequisite for a successful application
of diamond for the fabrication of electronic devices is availability of wafer diamond, i.e. large area, high quality, inexpensive,
diamond single crystal substrates. A step forward in this direction has been made recently. Diamond films grown on multilayer
substrate Ir/YSZ/Si(001) having qualities close those of homoepitaxial diamond have been reported recently. 相似文献
20.
A set of new porous materials, namely zeolite nanocage schwarzite-like crystals with the elements of both nanotubes and fullerenes in the structure is proposed as a result of ab initio and density-functional theory calculations. Twelve new Extradiamond phases of boron nitride, carbon, silicon and silicon carbide are calculated as three different hybridized crystals. The details of recently synthesized Explosion-BN (E-BN) phase are highlighted for the first time with electronic structure and vibrational frequency analysis. E-BN is supposed to be sp 2/sp 3-hybridized FAU-zeolite structure with calculated unit cell of 12.177 Å and a band gap of 3.2 eV. Calculated IR bands for E-BN120 cluster and observed experimentally E-BN absorption spectrum are well-correlated with appropriate IR spectra of FAU-zeolite. Armchair and zig-zag nanotubes are classified as (n,n,k) and (n,0,k), respectively, where k is the number of hexagons along the nanotube axis. Novel materials are proposed as (n,m,k)-FTC, where FTC stands for framework type code. We also indicate the possibility of creation of filled hybrid networks of different segment lengths, radii and compositions for thermoelectric and novel device applications. 相似文献