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1.
The effect of electron and ion beam irradiation on the SiL vv Auger spectra of SiO2, Si3N4 and Si-oxynitride films was measured by the relative intensity of the 92 eV signal, characteristic for the formation of “free” silicon during irradiation. While in Si-oxynitride (O/N = 0.37) the beam effects were almost negligible, some damage was found in Si3N4, but SiO2 appeared to be extremely sensitive for electron and ion beam irradiation. By low energy electron loss spectroscopy (ELS) of ion bombarded SiO2 and Si3N4 films new electron states due to broken Si-O and Si-N bonds could be determined within the band gap of the insulators. The measured energy losses were interpreted by means of electron energy level schemes of the amorphous films. 相似文献
2.
The yield and energy distribution of positive secondary ions emitted from Si under N2+ ion bombardment were measured. The obtained mass peaks correspond to three types of secondary ion species, that is, physically sputtered ions (Si+, Si2+), chemically sputtered ions (SiN+ Si2N+) and doubly charged ions (Si2+). The dependence of secondary ion emission on the primary ion energy was studied in a range of 2.0–20.0 keV. The yields of physically and chemically sputtered ions were almost independent of the primary ion energy. The yield of the doubly charged ion strongly depended on the primary ion energy. The energy distribution of secondary ions of the three types showed the same dependence on the primary ion energy. The most probable energy of the distribution increased with the primary ion energy. On the other hand, for the energy distribution curves of sputtered ions, the tail factors N in E?N were constant and showed a m/e dependence. 相似文献
3.
Xiaoming Teng 《Journal of luminescence》2010,130(5):851-854
The Sr2Si5N8:Eu2+ phosphors, both undoped and doped with Tm3+, were synthesized by high temperature solid-state method. The XRD pattern shows that only Sr2Si5N8 phase is formed whatever Tm3+ was doped or not. The peak positions of both phosphors are centered at 612 nm which is assigned to the 4f65d→4f7 transition of Eu2+. It implies that the crystal field, which affects the 5d electron states of Eu2+, is not changed dramatically after the phosphor is doped with Tm3+. The afterglow time is about 10 min after Tm3+ ion is introduced into the phosphor. The concentration of Tm3+ has little influence on the afterglow time of the phosphor. The depths of trap energy level of the two phosphors were calculated based on the TL spectra. The depths of Sr2Si5N8:Eu2+ and Sr2Si5N8:Eu2+, Tm3+ are 1.75 and 1.01 eV, respectively. 相似文献
4.
S. N. Morozov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(4):660-663
The spectra of secondary ion emission under the bombardment of a B-doped Si target by multiply charged Si q+ ions (q = 1?C5) have been studied in the energy range of 1 to 10 keV per unit of charge. A multifold increase in the yield of secondary cluster Sk n + ions, multiply charged Si q/+ ion (q = 1?C3), and H+, C+, B+, Si2N+, Si2O+ is observed as the charge of the multiply charged ions increases. The increase in the yield of secondary ions with increasing charge of the multiply charged-ion charge is most significant for ions with relatively high ionization potentials. 相似文献
5.
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
6.
《Current Applied Physics》2015,15(10):1160-1167
Due to growing demand on discovering new materials for light-emitting diodes devices, many efforts were made to discover and characterize new inorganic materials such as phosphors. Using the full potential method within density functional theory the electronic and optical properties of BaAl2Si3O4N4 and BaAlSi4O3N5 semiconductors have been investigated. The electronic structure and the optical properties of these phosphors were calculated through a reliable approach of modified Beck-Johnson (mBJ) approach. We found that BaAl2Si3O4N4 and BaAlSi4O3N5 have wide direct band gaps positioned at Γ about 5.846 and 4.96 eV respectively. The optical properties, namely the dielectric function, optical reflectivity, refractive index and electron energy loss, are reported for radiation up to 15 eV. Our study suggests that BaAl2Si3O4N4 and BaAlSi4O3N5 could be promising materials for applications in the LEDs devices and optoelectronics areas of research. 相似文献
7.
8.
为了揭示Ti_Si_N复合膜中Si3N4界面相的存在方式及其对薄膜力学 性能的影响 ,采用x射线衍射仪、高分辨透射电子显微镜、俄歇电子能谱仪和显微硬度仪对比研究了磁 控溅射Ti_Si_N复合膜和TiN/Si3N4多层膜的微结构和力学性能. 实 验结果表明 ,Ti_Si_N复合膜均形成了Si3N4界面相包裹TiN纳米晶粒的微结构. 其中低Si 含量的Ti_Si_N复合膜中Si3N4界面相的厚度小于1nm,且以晶体态 存在,薄膜 呈现高硬度. 而高Si含量的Ti_Si_N复合膜中的Si3N4界面相以非晶 态存在,薄 膜的硬度也相应降低. 显然,Ti_Si_N复合膜中Si3N4界面相以晶体 态形式存在 是薄膜获得高硬度的重要微结构特征,其强化机制可能与多层膜的超硬效应是相同的.
关键词:
Ti-Si-N复合膜
界面相
微结构
超硬效应 相似文献
9.
研究了Si3N4层在ZrN/Si3N4纳米多层膜中的晶化现象及其对多层膜微结构与力学性能的影响. 一系列不同Si3N4层厚度的ZrN/Si3N4纳米多层膜通过反应磁控溅射法制备. 利用X射线衍射仪、高分辨透射电子显微镜和微力学探针表征了多层膜的微结构和力学性能. 结果表明,由于受到ZrN调制层晶体结构的模板作用,溅射条件下以非晶态存在的Si3N4层在其厚度小于0.9 nm时被强制晶化为NaCl结构的赝晶体,ZrN/Si3N4纳米多层膜形成共格外延生长的柱状晶,并相应地产生硬度升高的超硬效应. Si3N4随层厚的进一步增加又转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低. 相似文献
10.
The luminescence properties of lanthanum silicon oxynitride(La-Si-O-N) series doped by trivalent Ce ions have been investigated to seek for tunable wavelength-conversion phosphor for white light emitting diode applications.Four compound hosts of LaSiO2N,La4Si2O7N2,La5Si3O12 N,and La2Si6O3N8 were synthesized and examined in this work.Crystallographic examination for the equal amount of Ce 3+ substitution indicated that the covalency degree decreased in a sequence LaSiO2 N > La2Si6O3N8 > La4Si2O7N2 > La5Si3O12 N,not simply in correlation to the ratio of N3/O2.Excitation and emission spectrum measurements showed the main features of Ce3+ luminescence in the series:the centre of gravity of 5d bands depends on crystal-field splitting more strongly than that on covalency of Ce-N bonding;nephelauxetic effect could not be observed clearly for the investigated series;to some extent Stokes shift was dominated by crystal-field splitting rather than Ce-N covalency degree. 相似文献
11.
Porous Si3N4 ceramics with photoluminescence properties were prepared by pressureless sintering using α-Si3N4 powder as raw material and Eu2O3 as sintering additive. Chemical composition, phase formation, microstructure and photoluminescence properties of porous Si3N4 ceramics were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence measurements (PL/PLE). The results show that single Eu2O3 additive promotes α→β transformation but not significant densification. A broad band emission center at 570 nm assigned to Eu2+ is observed, Eu3+ in Eu2O3 is (partially) converted to Eu2+ by reaction with Si3N4, which results in a lower β aspect ratio and β-content compared to the other Ln (Ln=lanthanide) oxide additives. 相似文献
12.
Shuangyou Zhang Toby Bi Irina Harder Olga Ohletz Florentina Gannott Alexander Gumann Eduard Butzen Yaojing Zhang Pascal Del'Haye 《Laser \u0026amp; Photonics Reviews》2024,18(4):2300642
Silicon-nitride-on-insulator (Si3N4) photonic circuits have seen tremendous advances in many applications, such as on-chip frequency combs, Lidar, telecommunications, and spectroscopy. So far, the best film quality has been achieved with low pressure chemical vapor deposition (LPCVD) and high-temperature annealing (1200°C). However, high processing temperatures pose challenges to the cointegration of Si3N4 with pre-processed silicon electronic and photonic devices, lithium niobate on insulator (LNOI), and Ge-on-Si photodiodes. This limits LPCVD as a front-end-of-line process. Here, ultralow-loss Si3N4 photonics based on room-temperature reactive sputtering is demonstrated. Propagation losses as low as 5.4 dB m−1 after 400°C annealing and 3.5 dB m−1 after 800°C annealing are achieved, enabling ring resonators with highest optical quality factors of > 10 million and an average quality factor of 7.5 million. To the best of the knowledge, these are the lowest propagation losses achieved with low temperature Si3N4. This ultralow loss enables the generation of microresonator soliton frequency combs with threshold powers of 1.1 mW. The introduced sputtering process offers full complementary metal oxide semiconductor (CMOS) compatibility with front-end silicon electronics and photonics. This could enable hybrid 3D integration of low loss waveguides with integrated lasers and lithium niobate on insulator. 相似文献
13.
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
14.
S. Camelio J. Toudert D. Babonneau T. Girardeau 《Applied physics. B, Lasers and optics》2005,80(1):89-96
The variation of the optical properties of embedded metallic nanoclusters induced by changes of their morphology is investigated by an approach combining electron microscopy, grazing incidence small angle X-ray scattering and transmission measurements. For this purpose, silver nanoclusters with various shapes (from prolate to oblate) and embedded in an amorphous Si3N4 matrix are elaborated by ion beam sputtering using either a co-deposition process or an alternate sputtering. Moreover, a post-irradiation with Ar+ ions (at different fluences and low incident energy of 75–100 keV) is used to complement the fabrication process in order to tailor the nanoclusters shape. Prolate and oblate nanoclusters become then more spherical leading to a spectral shift of their surface plasmon resonance. PACS 61.46.+w; 78.67.Bf; 81.07.b; 81.15.cd 相似文献
15.
Klaus Schwidtal 《Surface science》1978,77(3):523-536
A theoretical model is proposed on how a Si dangling bond associated with an oxygen vacancy on a SiO2 surface (Es′ center) should be observed by Auger electron spectroscopy (AES). The Auger electron distribution NA(E) for the L23VV transition band is calculated for a stoichiometric SiO2 surface, and for a SiOx surface containing Si-(e?O3) coordinations. The latter is characterized by an additional L23VD transition band, where D is the energy level of the unpaired electron e?. The theoretical NA(E) spectra are compared with experimental N(E) spectra for a pristine, and for an electron radiation damaged quartz surface. Agreement with the theoretical model is obtained if D is assumed to lie ≈2 eV below the conduction band edge. This result shows that AES is uniquely useful in revealing the absolute energy level of localized, occupied surface defect states. As the L23VD transition band (main peak at 86 eV) cannot unambiguously be distinguished from a SiSi4 coordination L23VV spectrum (main peak at 88 eV), supporting evidence is presented as to why we exclude a SiSi4 coordination for our particular experimental example. Application of the Si-(e?O3) model to the interpretation of SiO2Si interface Auger spectra is also discussed. 相似文献
16.
17.
采用反应磁控溅射法制备了一系列具有不同Si3N4层厚度的AlN/Si3N4纳米多层膜,利用X射线衍射仪、高分辨透射电子显微镜和微力学探针表征了多层膜的微结构和力学性能.研究了Si3N4层在AlN/Si3N4纳米多层膜中的晶化现象及其对多层膜生长结构与力学性能的影响.结果表明,在六方纤锌矿结构的晶体AlN调制层的模板作用下,通常溅射条件下以非晶态存在的Si3N4层在其厚度小于约1nm时被强制晶化为结构与AlN相同的赝形晶体,AlN/Si3N4纳米多层膜形成共格外延生长的结构,相应地,多层膜产生硬度升高的超硬效应.Si3N4随层厚的进一步增加又转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低.分析认为,AlN/Si3N4纳米多层膜超硬效应的产生与多层膜共格外延生长所形成的拉压交变应力场导致的两调制层模量差的增大有关.
关键词:
3N4纳米多层膜')" href="#">AlN/Si3N4纳米多层膜
外延生长
赝晶体
超硬效应 相似文献
18.
In this work, we investigated the effect of water-vapor treatment on the surface morphology of SiO2 and Si3N4 insulators before and after Co60 gamma-ray irradiation by using the atomic force microscopy (AFM) operated under non-contact mode. Before irradiation, no apparent surface morphology change was found in SiO2 samples even they were water vapor treated. However, bright spots were found on post-irradiated water-vapor-treated SiO2 sample surfaces but not on those without water-vapor treatment. We attributed the bright spots to the negative charge accumulation in the oxide due to charge balancing between hydroxyl (OH−) ions adsorbed on SiO2 surface and electron-hole pairs (ehps) generated during irradiation since they can be annealed out after low temperature annealing process. On the contrary, no bright spots were observed on post-irradiated Si3N4 samples with and without water-vapor treatment. This result confirms that Si3N4 is a better water-resist passivation layer than SiO2 layer. 相似文献
19.
INVESTIGATION ON THE COMPOSITION AND STRUCTURE OF SILICON NITRIDE FILM PREPARED BY ECR-PECVD 总被引:2,自引:0,他引:2 下载免费PDF全文
In this paper, the effect of temperature on the composition and structure of the Si3N4 thin film is investigated. X-ray diffraction pattern and transmission electron microscope (TEM) analyses show that the Si3N4 film undergoes the transition from amorphous to crystalline phase with increasing deposition temperature. Infra-red qualitative analysis shows that the content of hydrogen decreases with increasing deposition temperature.The stoichiometric of Si3N4 is investigated by X-ray photoelectron spectroscopy or electron spectroscopy for chemical analysis. 相似文献
20.
Rajesh Kumar S. Asad Ali A. H. Naqvi H. S. Virk Udayan De D. K. Avasthi Rajendra Prasad 《Indian Journal of Physics》2009,83(7):969-976
A wide variety of material modifications in polymers have been studied by using ion irradiation techniques. Extensive research
has focused on to Swift Heavy Ions (MeV’s energy), probably because of good controllability and the large penetration length
in polymers. High energy ion irradiation tends to damage polymers significantly by electronic excitation and ionization. It
may result into the creation of latent tracks and can also cause formation of radicals such as ablation, sputtering, chain
scission and intermolecular cross-linking, creation of triple bonds and unsaturated bonds and loss volatile fragments. Polypropylene
polymer films of thickness 50 μm were irradiated to the fluences of 1 × 1010, 3 × 1010, 1 × 1011, 3 × 1011, 6 × 1011 and 1 × 1012 ions/cm2 with Si8+ ions of 100 MeV energy from Pelletron accelerator at Inter University Accelerator Centre (IUAC), New Delhi and Ne6+ ions of 145 MeV to the fluences of 108, 1010, 1011, 1012 and 1013 ions/cm3 from Variable Energy Cyclotron Centre, Kolkata. Optical modifications were characterized by UV towards the red end of the
spectrum with the increase of the fluence. Value of optical band gap E
g
shows a decreasing trend with ion fluence irradiated with both kinds of ions. Cluster size N, the number of carbon atoms per conjugation length increases with increasing ion dose. Cluster size also increases with the
increase of electronic stopping power.
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