共查询到20条相似文献,搜索用时 46 毫秒
1.
B. K. Kardashev B. I. Smirnov D. Singh K. C. Goretta A. R. de Arellano-López 《Physics of the Solid State》2003,45(3):477-481
The effect of temperature and vibrational strain amplitude on Young’s modulus and an ultrasound damping (internal friction) of ceramic boron nitride samples and silicon nitride/boron nitride fibrous monoliths was studied. It was shown that the elastic moduli and the elastic vibration decrement of the low-modulus BN ceramic and of the high-modulus Si3N4/BN monoliths measured at small strain amplitudes (in the region of amplitude-independent internal friction) exhibit a noticeable temperature hysteresis. Temperature exerts the smallest effect on the amplitude-independent decrement and on the amplitude-dependent damping and Young’s modulus defect of a monolith whose filaments are arranged both along and perpendicular to the axis of a rodshaped sample. These parameters behave in the most complicated way in a sample with all its filaments aligned with the rod axis. The observed relations can be assigned to structural features of the monoliths and the considerable influence of transverse strain on the evolution of defect structure in the materials studied. 相似文献
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Changes of surface morphology following excimer laser (KrF, ArF) irradiation were investigated for three technical ceramic materials (TZP, PSZ, Si3N4). Zirconia samples exhibit a smooth and glass-like surface at the low power density regime, while at higher power densities colour changes were observed due to changes in the chemical composition of the bulk material. In the silicon nitride samples new crystals of specific orientation are formed, which could be crystalline silicon. 相似文献
4.
Imran Khan 《Physica B: Condensed Matter》2009,404(16):2395-2400
The effects of tellurium (Te) additives on electrical conductivity, dielectric constant and structural properties of sintered silicon nitride ceramics have been studied. Different amounts of Te (10% and 20%) were added as sintering additives to silicon nitride ceramic powders and sintering was performed. Microstructure and composition were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrical conductivity and dielectric constant (ε′) increase exponentially with temperature greater than 800 K. The electrical conductivity and dielectric constant increase but activation energy decreases from 0.72 to 0.33 eV with the increase of Te concentration. However, the conductivity increases five orders of magnitude at the concentration of 10% of Te in Si3N4. As the Te concentration increases the sintered silicon nitride ceramics become denser. These types of samples can be used as high temperature semiconducting materials. 相似文献
5.
Convergent Beam Electron Diffraction (CBED) experiments and simulations associated with Finite Element calculations were performed in order to measure strain and stress in a complex device such as periodic MOS transistors with a spatial resolution of about 2 nm and a sensitivity that could reach 50 MPa. A lamella of a thickness of about 475 nm was extracted from the wafer with the transistors by Focus Ion Beam (FIB) and was observed in cross-section in a Transmission Electron Microscope (TEM). When approaching the transistors, the HOLZ lines of the CBED patterns acquired in the silicon substrate, become broader and broader. This HOLZ line broadening, which is due to the stress relaxation in the thin foil, was used to determine quantitatively the strain and stress in the lamella and then in the bulk device. We showed that this procedure could be applied to a complex device. Two parameters, the intrinsic material strains – or equivalently the intrinsic material stresses – in the nickel silicide (NiSi) and nitride (Si3N4) layers on the top of the transistors gate, were successfully fitted by trial and error, in the procedure. 相似文献
6.
V. A. Gritsenko Yu. N. Novikov A. V. Shaposhnikov H. Wong G. M. Zhidomirov 《Physics of the Solid State》2003,45(11):2031-2035
The electronic structure and capturing properties of threefold coordinated silicon atoms (≡Si·) and the Si-Si bond in silicon nitride (Si3N4) were studied using the ab initio density functional theory. The results show that the previously proposed negative correlation energy (NCE) model is not applicable to Si3N4. The NCE model was proposed for interpreting the absence of the ESR signal for threefold coordinated silicon defects and suggested that an electron can transfer between two silicon defects. We proposed that the absence of this ESR signal is due to the creation of neutral diamagnetic Si-Si defects in Si3N4. This model offers the most fundamental theory for explaining the hole localization (memory) effect in silicon nitride. 相似文献
7.
Y. Sarov T. Ivanov A. Frank I. W. Rangelow 《Applied Physics A: Materials Science & Processing》2008,92(3):525-530
The presented work reports the fabrication of 4×32 arrays of fully addressable proximity probes, which are initially and controllably
off-plane deflected (bent). Such a deflection is required for the simultaneous approach and scanning of all cantilevers. It
is realized by deposition of the silicon cantilevers with Si3N4 film inducing tensile stress. ANSYS simulations are used to calculate the off-plane deflection for different thickness of
the cantilever and the Si3N4 layer and compared with experimentally obtained values. Cantilever arrays with set bending up to 50 μm, employing LPCVD silicon
nitride film with a tensile stress of 750 MPa are fabricated. 相似文献
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本文用X射线径向分布函数法研究了室温到1000℃不同退火条件下的纳米非晶氮化硅样品的微结构和键合特征。观察到占庞大体积百分数界面不是“gas-like”结构,而是与非晶纳米粒子不同的新的短程序结构。Si—N键长和最近邻原子配位数(CN)均比传统Si3N4小,并存在大量的Si悬键和不饱和键。纳米氮化硅与传统Si3N4饱和共价键不同,是含有大量非饱和键和悬键的非典型共价键结构。由于键配位的不饱和特征,纳米非晶氮化硅的分子式应写作Si3-xN4-y。纳米非晶氮化硅出现强极性与非饱和键和悬键有密切的关系。
关键词: 相似文献
10.
Mahesh Kumar Mohana K. RajpalkeBasanta Roul Thirumaleshwara N. BhatNeeraj Sinha A.T. KalghatgiS.B. Krupanidhi 《Applied Surface Science》2011,257(6):2107-2110
Ultra thin films of pure silicon nitride were grown on a Si (1 1 1) surface by exposing the surface to radio-frequency (RF) nitrogen plasma with a high content of nitrogen atoms. The effect of annealing of silicon nitride surface was investigated with core-level photoelectron spectroscopy. The Si 2p photoelectron spectra reveals a characteristic series of components for the Si species, not only in stoichiometric Si3N4 (Si4+) but also in the intermediate nitridation states with one (Si1+) or three (Si3+) nitrogen nearest neighbors. The Si 2p core-level shifts for the Si1+, Si3+, and Si4+ components are determined to be 0.64, 2.20, and 3.05 eV, respectively. In annealed sample it has been observed that the Si4+ component in the Si 2p spectra is significantly improved, which clearly indicates the crystalline nature of silicon nitride. The high resolution X-ray diffraction (HRXRD), scanning electron microscopy (SEM) and photoluminescence (PL) studies showed a significant improvement of the crystalline qualities and enhancement of the optical properties of GaN grown on the stoichiometric Si3N4 by molecular beam epitaxy (MBE). 相似文献
11.
Charge injection behaviours in silicon nitride of an Al/Si3N4/n-Si metal?Cinsulator?Csemiconductor (MIS) device are systematically studied before and after applying different high constant DC bias conditions with the aim of controlling charge accumulation in the dielectric when a high actuation voltage is applied. We found that both polarity and magnitude of charge accumulation in silicon nitride depend on the biasing direction. Charge injection from the semiconductor to the silicon nitride always dominates over charge injection from the Al electrode to the silicon nitride. Negative charge accumulation happens in silicon nitride when the Al electrode is positively biased, and positive charge accumulation occurs in silicon nitride when the Al electrode is negatively biased. The positive charge accumulation is much bigger than the negative charge accumulation under the same magnitude of stress voltage. Furthermore, the experimental results also show that the charge injection level exponentially increases with the applied voltage across the silicon nitride. These observed experimental results can be well explained by a modified Fowler?CNordheim tunnelling charge injection model, which takes into account the roles of both electrons and holes in the process of charge injection. 相似文献
12.
Deepak Kumar Basa 《Central European Journal of Physics》2010,8(3):400-407
Silicon nitride films have emerged as the possible future dielectrics for ultra large scale integration (ULSI). Because the
interface state density of silicon nitride/silicon interface in metal insulator semiconductor (MIS) configuration is more
than an order of magnitude larger than that of silicon dioxide/silicon interface, plasma treatment studies on silicon nitride
films have been undertaken for the possible improvement. Accordingly, silicon nitride films of various composition have been
prepared by plasma enhanced chemical vapor deposition (PECVD) system using silane(SiH4) and ammonia(NH3) with nitrogen(N2) as the diluent and MIS devices have been fabricated with as well as without plasma treated silicon nitride as the insulator.
A considerable improvement in the silicon nitride/silicon interface is observed on ammonia plasma treatment while nitrous
oxide(N2O) plasma treatment studies have resulted in the establishment of a novel plasma oxidation process. 相似文献
13.
Two-layered aluminium nitride (AlN)/silicon nitride microbridges were fabricated for microbridge tests to evaluate the elastic modulus, residual stress and tensile strength of the AlN films. The silicon nitride layer was added to increase the robustness of the structure. In a microbridge test, load was applied to the centre of a microbridge and was gradually increased by a nano-indenter equipped with a wedge tip until the sample was broken, while displacement was recorded coherently. Measurements were performed on single-layered silicon nitride microbridges and two-layered AlN/silicon nitride microbridges respectively. The data were fitted to a theory to derive the elastic modulus, residual stress and tensile strength of the silicon nitride films and AlN films. For the AlN films, the three parameters were determined to be 200, 0.06 and 0.3?GPa, respectively. The values of elastic modulus obtained were consistent with those measured by conventional nano-indentation method. The tensile strength value can be used as a reference to reflect the maximum tolerable tensile stress of AlN films when they are used in micro-electromechanical devices. 相似文献
14.
B. I. Smirnov Yu. A. Burenkov B. K. Kardashev D. Singh K. C. Goretta A. R. de Arellano-López 《Physics of the Solid State》2001,43(11):2094-2098
A study is reported on the effect of temperature and elastic vibration amplitude on Young’s modulus E and internal friction in Si3N4 and BN ceramic samples and Si3N4/BN monoliths obtained by hot pressing of BN-coated Si3N4 fibers. The fibers were arranged along, across, or both along and across the specimen axis. The E measurements were carried out under thermal cycling within the 20–600°C range. It was found that high-modulus silicon-nitride specimens possess a high thermal stability; the E(T) dependences obtained under heating and cooling coincide well with one another. The low-modulus BN ceramic exhibits a considerable hysteresis, thus indicating evolution of the defect structure under the action of thermoelastic (internal) stresses. Monoliths demonstrate a qualitatively similar behavior (with hysteresis). This behavior of the elastic modulus is possible under microplastic deformation initiated by internal stresses. The presence of microplastic shear in all the materials studied is supported by the character of the amplitude dependences of internal friction and the Young’s modulus. The experimental data obtained are discussed in terms of a model in which the temperature dependences of the elastic modulus and their features are accounted for by both microplastic deformation and nonlinear lattice-atom vibrations, which depend on internal stresses. 相似文献
15.
In the presented paper radiation effects in silicon-silicon dioxide systems in the presence of additional tensile and compressive stresses were investigated. These stresses were produced by placing additional layers of SiO2 or Si3N4 on the back side of oxidized silicon wafers.The results obtained indicate that relaxation takes place in the oxide during irradiation and leads to the decrease of the compressive stress in the oxide film. Relaxation of strained bonds causes defect generation and the increase of the oxide charge density. This increase is larger for oxides with higher level of compressive stress. No significant changes of the density of surface states were observed since the additional coatings did not affect the strain gradient in the SiO2. 相似文献
16.
Characterization of SiC and Si<Subscript>3</Subscript>N<Subscript>4</Subscript> nanoparticles and their aqueous dispersions 总被引:1,自引:0,他引:1
Nanoparticles of SiC and Si3N4 were previously used to obtain electroless NiP/particles nanocomposites. The incorporation process was very different, depending
on the particle: SiC tended to agglomerate and had a high incorporation level; Si3N4 particles were not aggregated, but their incorporation level was very low. To try to explain these differences, the particles
and their aqueous dispersions were characterized. Although the as-received products were both oxidized and of the identical
mean size, results showed that the size distributions and the surface oxidation products were rather different. The zeta potential
in water dispersions was similar and negative for both particles but, as the electrolyte ions were introduced, it showed a
different evolution: nitride particles retained a small negative charge and carbide was almost uncharged. The overall results
obtained in this study explain the different behavior of both ceramic particles and provide possible solutions to improve
their co-deposition with nickel. 相似文献
17.
Murat Durandurdu 《哲学杂志》2016,96(11):1110-1121
We report the electronic structure and topology of a heavily Si-doped amorphous aluminium nitride (Al37.5Si12.5N50) using ab initio simulations. The amorphous Al37.5Si12.5N50 system is found to be structurally similar to pure amorphous aluminium nitride. It has an average coordination number of about 3.9 and exhibits a small amount of Si–Si homopolar bonds. The formation of Si–Al bonds is not very favourable. Electronic structure calculations reveal that the Si doping has a negligible effect on the band gap width but causes delocalization of the valence band tail states and a shift of the Fermi level towards the conduction band. Thus, amorphous Al37.5Si12.5N50 alloys show n-type conductivity. 相似文献
18.
Mechanical strains along oxide edges of semiconductor devices with oxide isolation were studied by real-time x-ray topography
in the temperature range from 20 to 1100°C. Due to the different thermal expansion coefficients of silicon and oxide, the
strain at these edges decreases continuously with increasing temperature. The strength of the strain pattern corresponds to
the structure size. The strain depends also on the thickness of the Si3N4 layer though the nitride was removed before the experiment. During the first heat treatment the contrast splits up into two
lines at about 780°C. 相似文献
19.
S. S. Nekrashevich V. A. Gritsenko R. Klauser S. Gwo 《Journal of Experimental and Theoretical Physics》2010,111(4):659-666
Charge transfer ΔQ = 0.35e at the Si-N bond in silicon nitride is determined experimentally using photoelectron spectroscopy, and the ionic formula
of silicon nitride Si3+1.4N4−1.05 is derived. The electronic structure of α-Si3N4 is studied ab initio using the density functional method. The results of calculations (partial density of states) are compared
with experimental data on X-ray emission spectroscopy of amorphous Si3N4. The electronic structure of the valence band of amorphous Si3N4 is studied using synchrotron radiation at different excitation energies. The electron and hole effective masses m
e
* ≈ m
h
* ≈ 0.5m
e
are estimated theoretically. The calculated values correspond to experimental results on injection of electrons and holes
into silicon nitride. 相似文献
20.
《Superlattices and Microstructures》2000,27(5-6)
We explore the hydrogen-related microstructures involved in hot electron defect creation at the Si(100)–SiO2interface of metal-oxide-semiconductor field effect transistors. Based on the energetics of hydrogen desorption from the interface between silicon and silicon-dioxide, we argue that the hard threshold for hydrogen-related degradation may be considerably lower than the previously assumed value of 3.6 eV. Also, hydrogen atoms released from Si–H bonds at the interface by hot electron stress are trapped in bulk silicon near the interface. 相似文献