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1.
Liu Changshi 《Vacuum》2004,75(1):51-55
The first level plasmons of Si in the pure Si state, in the SiO2 state and in the Si3N4 state (corresponding to bonding energy 116.95, 122.0 and 127.0 eV) were investigated directly with X-ray photoelectron spectroscopy before and after 60Co radiation. The experimental results demonstrate that there existed two interfaces, one consisted of plasmons of Si in the Si3N4 and SiO2 states, while another was made of plasmons of Si in the pure Si state and in the SiO2 state. When the Si3N4-SiO2-Si samples were irradiated by 60Co, the interface at Si3N4/SiO2 was extended and at the same time the center of this interface moved towards the surface of Si3N4. The concentration of plasmon for silicon in the SiO2 state is decreased at the SiO2-Si interface, and the effects of radiation bias field on plasmons in the SiO2-Si interface are observable. Finally, the mechanism of experimental results is analyzed by the quantum effect of plasmon excited by the photoelectron. 相似文献
2.
The quasistatic C-V technique can be used under certain conditions to obtain the energy distribution of the interface states located in the silicon band gap of an MNOS system. An increase of the SiO2 thickness leads to a considerable decrease in the interface state density around the mid-gap. It is shown that, for the thin oxide MNOS capacitors we measured, the Si3N4SiO2 interface dominates over the SiSiO2 interface in producing interface states with a high density. 相似文献
3.
Liu Changshi 《Vacuum》2003,72(1):91-95
The interfacial structures of double interfaces system of Si3N4/SiO2/Si were examined using X-ray photoelectron spectroscopy (XPS) before and after 60Co radiation. The experimental results demonstrate that there existed two interfaces, one consisted of Si3N4 and SiO2, while another was made of Si and SiO2, the interface between SiO2 and Si was extended towards the interface of the Si3N4/SiO2 meanwhile the center of the former interface was removed in the direction of the latter interface by 60Co. The concentration of silicon in the Si3N4 state (BE 101.8 eV) was decreased with the variation of radiation dosage as well as bias field within the SiO2-Si interface, remarkably. The mechanism for the experimental results is analyzed. 相似文献
4.
《Materials Letters》2004,58(7-8):1383-1386
Hot-pressure sintered β-Si3N4 ceramic was bonded to itself using Y2O3–Al2O3–SiO2–TiO2 mixtures. Reactive behavior at interface between Si3N4 and Y2O3–Al2O3–SiO2–TiO2 mixtures during silicon nitride ceramic joining was studied by means of scanning electron microscopy (SEM), electron probe microanalyses (EPMA), X-ray diffraction (XRD) and auger electron spectroscopy (AES). The joint strength under different bonding conditions was measured by four-point bending tests. The results of EPMA, AES and XRD analyses show that the liquid glass solder reacts with silicon nitride at interface, forming the Si3N4/Y–Si–Al–Ti–O–N glass/TiN/Y–Si–Al–O glass gradient interface. From the results of four-point bending tests, it is known that with increase of bonding temperature and holding time, the joint strength increased reaching a peak, and then decreased. The maximum joint strength of 200 MPa measured by the four-point bending tests is obtained for silicon nitride bonded at 1823 K for 30 min. 相似文献
5.
《Thin solid films》2005,471(1-2):166-169
Thermally stimulated exoelectron emission has been applied for high-resolution depth profiling of traps in amorphous SiO2/Si3N4/SiO2 (ONO) dielectric stacks used in silicon–oxide–nitride–oxide–silicon (SONOS) memory devices. It is shown that maximum density of traps responsible for charge storage in ONO structures is at the interface between top silicon oxide and silicon nitride in ONO. 相似文献
6.
Thin (d ? 10 nm) films of almost stoichiometric silicon nitride were prepared by implanting nitrogen ions with energies below 5 keV into silicon with subsequent thermal annealing. A combination of Auger electron spectroscopy (AES) and electron energy loss spectroscopy (ELS) was used to determine the chemical composition and to investigate the chemical bonding states of the thin films. The spectra are in good agreement with those obtained for Si3N4 produced by chemical vapour deposition. The use of AES and electron ELS allowed the stepwise formation of the SiN bonds to be investigated for the first time, and hence further information about the electronic structure of Si3N4 was obtained. Depth-concentration profiles for nitrogen are presented. 相似文献
7.
Hee-Wook You 《Thin solid films》2010,518(22):6460-7485
The electrical characteristics of tunnel barrier engineered charge trap flash (TBE-CTF) memory of MAHONOS (Metal/Al2O3/HfO2/SiO2/Si3N4/SiO2/Si) structure were investigated. The stack of SiO2/Si3N4/SiO2 films were used as engineered tunnel barrier, HfO2 and Al2O3 films were used as charge trap layer and blocking oxide layer, respectively. For comparison, the electrical characteristics of MONOS (Metal/SiO2/Si3N4/SiO2/Si), MONONOS (Metal/SiO2/Si3N4/SiO2/Si3N4/SiO2/Si), and MAHOS (Metal/Al2O3/HfO2/SiO2/Si) were also evaluated. The energy band diagram was designed by using the quantum-mechanical tunnel model (QM) and then the CTF memory devices were fabricated. As a result, the optimized thickness combination of MAHONOS structure was confirmed. The tunnel barrier engineered MAHONOS CTF memory showed a considerable enhancement of program/erase (P/E) speeds, retention time and endurance characteristics. 相似文献
8.
Synthesis of 21R AlN polytypoids was investigated using Al and ultrafine SiO2 powder in a flowing nitrogen atmosphere by means of thermal gravity (TG), differential scanning calorimeter (DSC), X-ray diffractometer (XRD) and scanning electronic microscope (SEM) linked with energy dispersive spectrometer (EDS). The results showed that the formation mechanism of AlN polytypoids was different from that in reaction sintering process using Si3N4, AlN, Al2O3 and other sintering additive as raw materials. It was suggested that firstly Al reduce SiO2 into Si and is also nitrided into AlN, then AlN, Al2O3 and SiO2 dissolve into silicon liquid until the AlN polytypoids precipitate in saturated liquid in a flowing nitrogen atmosphere at lower than 1700 °C. 相似文献
9.
The deposition of in situ boron doped silicon films from boron trichloride BCl3 and silane SiH4 in a conventional low-pressure chemical vapour deposition reactor has been studied for high boron doping levels and two kinds of substrates (SiO2 and Si3N4). On the basis of transmission electron microscopy and X-ray photoelectron spectroscopy results, these films appear to be highly sensitive to the local electronic environment of both substrate and deposited atoms. Indeed, beyond a critical doping level, this material becomes more and more amorphous, due to the occurrence of a particular organization of boron atoms in the silicon matrix. This behaviour results in a lowering of the well-known boron enhancement effect for deposition rate and crystalline fraction. 相似文献
10.
An electron microprobe technique is described for determining the thickness of SiO2 and Si3N4 in wafers and devices. The technique is based on the measurement of oxygen and silicon X-ray intensities at 2.5 kV and 10 kV through the nitride overlay. At the lower accelerating voltage, both intensities decrease with increasing nitride thickness owing to absorption and silicon distribution in depth. The SiO2 thickness, however, is obtained by measuring the oxygen X-ray intensity at the higher voltage (10 kV), because at this voltage the oxygen intensity is not dependent on the nitride thickness.Empirical relationships expressing Si3N4 thickness in terms of Si and O X-ray intensities and SiO2 thickness are derived. 相似文献
11.
The reaction between silicon substrates and ammonia present in the systems GaCl (AlCl3)-NH3-H2 (He) during the vapour phase epitaxy of Group III nitrides has been investigated. Silicon was treated with an NH3-HCl-H2 mixture at a constant temperature in the range873–1273 K. Using electron spectroscopy for chemical analysis measurements layers of Si3N4 and Si3N4-SiO2 were detected at the silicon surface. Reflection high energy electron diffraction tests indicated the amorphous nature of this passivating layer which was found partially or completely to prevent epitaxial deposition of the Group III nitrides. The deposits of GaN on Si(111) and Si(100) were either polycrystalline or textured and an amorphous Si3N4-SiO2 interface was found. 相似文献
12.
Valence and core electron excitations were measured for thermal SiO2 films and chemical-vapour-deposited Si3N4 films using low energy electron loss spectroscopy (ELS). A reasonable interpretation of the spectra can be obtained using electron energy level diagrams derived from optical and X-ray experiments and from theoretical calculations using literature values. The electron levels of these amorphous materials can then be described by localized molecular states. The ELS spectra show the formation of basic [SiO4] and [SiN4] tetrahedra and the existence of Si-Si bonds in mixed tetrahedra, suggesting a deviation from ideal stoichiometry and the presence of broken Si-O and Si-N bonds. Auger spectra have also been measured for elemental silicon, for SiO2 and for Si3N4 and are discussed in terms of chemical shifts and line shape. 相似文献
13.
《材料科学技术学报》2019,35(12):2767-2771
In order to modify the interface, SiON coating was introduced on the surface of silicon nitride fiber by perhydropolysilazane conversion method. Si3N4f/SiO2 and Si3N4f/SiONc/SiO2 composites were prepared by sol-gel method to explore the influence of SiON coating on the mechanical properties of composites. The results show that with the protection of SiON coating, Si3N4 fiber enjoys a strength increase of up to 24.1% and Si3N4f/SiONc/SiO2 composites have a tensile strength of 170.5 MPa and a modulus of 26.9 GPa, respectively. After 1000 °C annealing in air for 1 h, Si3N4f/SiONc/SiO2 composites retain 65.0% of their original strength and show a better toughness than Si3N4f/SiO2 composites. The improvement of mechanical properties is attributing to the healing effect of SiON coating as well as its intermediate coefficient of thermal expansion between Si3N4 fiber and SiO2 matrix. 相似文献
14.
We present the surface modification of Si(111) into silicon nitride by exposure to energetic N2+ ions. In-situ UHV experiments have been performed to optimize the energy and fluence of the N2+ ions to form silicon nitride at room temperature (RT) and characterized in-situ by X-ray photoelectron spectroscopy. We have used N2+ ion beams in the energy range of 0.2–5.0 keV of different fluence to induce surface reactions, which lead to the formation of SixNy on the Si(111) surface. The XPS core level spectra of Si(2p) and N(1s) have been deconvoluted into different oxidation states to extract qualitative information, while survey scans have been used for quantifying of the silicon nitride formation, valence band spectra show that as the N2+ ion fluence increases, there is an increase in the band gap. The secondary electron emission spectra region of photoemission is used to evaluate the change in the work function during the nitridation process. The results show that surface nitridation initially increases rapidly with ion fluence and then saturates. 相似文献
15.
G.R. Moghal 《Thin solid films》1978,55(3):329-346
The influence of gold in the Si/SiO2 system has been studied both theoretically and experimentally. The gold is found to introduce two regions of shallow acceptor surface state energy levels in the silicon band gap at the SiSiO2 interface: one at 0.09 eV from the valence band edge and the other at 0.13 eV from the conduction band edge. It is tentatively postulated that both the surface state energy levels are due to gold atoms in substitutional sites.The two deep normal bulk gold energy levels in silicon do not seem to occur at the SiSiO2 interface.Finally a model of gold diffusion is suggested, and gold is found to diffuse through the bulk silicon by a complex interstitial and substitutional mechanism. 相似文献
16.
The present paper reports the results of studying the characteristics of the etching process of multi-layered materials (Si3N4/SiO2/Si and SiO2/Si) and of cleaning technological chambers covered with silicon nitride films (Si3N4) in a NF3 RF capacitive discharge. The process of chamber cleaning was monitored with a mass spectrometer. The gas pressure, RF voltage amplitude, current-voltage phase shift, ohmic current as well as the second harmonic of the RF current were also recorded. The opportunity of using these parameters for end-point detection of etching and plasma cleaning is discussed. It is found that the second harmonic of the RF current may be successfully used for end-point detection of multi-layered materials etching and to monitor the cleaning process of technological chambers. The cleaning of chambers of complicated design may possess a double-stage pattern. 相似文献
17.
Electron energy -loss spectroscopy has been used to investigate the interface between a Y2O3 film and the silicon substrate. The chemical composition of the interface layer is revealed to be nearly pure amorphous SiO2. Yttrium silicates are found at the Y2O3/SiO2 interface region. The formation of the interfacial yttrium silicates has been interpreted by the direct chemical reaction between the deposited Y2O3 film and the SiO2 interface layer. The Si L23 and O K edges of yttrium silicates (Y2SiO5 and Y2Si2O7) have been calculated by the first-principle full multiple - scattering method. The theoretical results are consistent with the experimental spectra, which confirms the formation of yttrium silicates. 相似文献
18.
S. Cueff C. Labbé L. Khomenkova O. Jambois P. Pellegrino B. Garrido C. Frilay R. Rizk 《Materials Science and Engineering: B》2012,177(10):725-728
This study compares the erbium emission from different Si-rich silicon oxynitrides matrices fabricated by magnetron sputtering. The Er-doped layers were grown by two different sputtering configurations: (i) standard co-sputtering of three confocal targets (Er2O3, Si3N4 and SiO2) under Ar plasma, and (ii) reactive co-sputtering under Ar + N2 plasma of either three (Er2O3, pure Si and SiO2) or two targets (Er2O3 and pure Si). The last reactive configuration was found to offer the best Er3+ PL intensity at 1.5 μm. This highest PL intensity was found comparable to the corresponding emission from Er-doped silicon-rich silicon oxide. 相似文献
19.
The system of the nanoinclusions of Si in the SiO2 and Al2O3 matrix (SiO2:Si, Al2O3:Si) attracts great attention due to its ability of the luminescence in visible and near-IR range of spectrum. The influence of the P ion alloying on the electronic structure of nanocomposites was investigated. The P ion doping and post-annealed at T = 1000 °C (2 h) results in the enhancement of the photoluminescence (PL) peak connected with the Si nanocrystals. The electronic structure was investigated by X-ray photoelectron spectroscopy (XPS) and high-resolution electron energy losses spectroscopy (HREELS) methods. Ion surface modification and annealing forms the special nanostructure with Si nanocrystals in SiO2 and Al2O3 matrix having high density of interfaces with special atomic structure and various degree of oxidation of Si atoms on the boundaries. HREELS investigations show that the P ion doping increases the probability of interband transitions in SiO2:Si and Al2O3:Si composites. 相似文献
20.
Films prepared by radiofrequency pulsed plasma enhanced chemical vapor deposition from a mixture of silane (SiH4) and nitrous oxide (N2O) were studied. Variation of operating conditions (flow rate, deposition temperature ...) resulted in films with chemical compositions changing from hydrogenated silicon oxynitride (SiOxNy:H) to silicon oxide (SiOx:H). Infrared and Rutherford backscattering spectroscopy studies of the as-deposited films revealed different SiOx arrangements disturbed by Si-N bonds and H-Si ≡ Si(3 − x)Ox clusters depending on the substrate temperature and the N2O/SiH4 ratio. For films obtained using low N2O/SiH4 rations and annealed at temperature higher than 1273 K, Raman spectroscopy and microscopy analyses revealed the presence of silicon nanocrystals embedded in a matrix containing Si, O, and N. Spectroscopic ellipsometry revealed the presence of silicon nanocrystals along with two other amorphous phases (SiOxNy and SiO2) in annealed samples. The electrical characteristics of annealed films obtained from capacitance-voltage measurements indicated a stable charge trapping in ultra-thin SiOxNy layers. These preliminary results suggest that Si-nc containing silicon oxynitride layers can be potential candidates to be used in the floating gate fabrication of memory devices. 相似文献