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Journal ArticleDOI: 10.1016/S0168-583X(99)00773-9

Ion-beam irradiation effects on Ni3N/Si bilayers

Abstract: Nitrides, carbides and oxides are important ceramic materials for wide range of applications in coating, nuclear reactor and semiconductor technology The study of their bonding properties to metals and semiconductors, for instance via ion irradiation, is of great importance In this work, we report on the effects induced by 100 and 450 keV Xe+ ions in 70–100 nm Ni3N layers deposited on Si substrates Low-energy irradiation at 80 K was found to cause a preferential nitrogen loss in the near-surface regions and an increase in surface roughness of the Ni3N film After the 450 keV Xe+ ion irradiation, strong mixing and the formation of Ni2Si and Si3N4 phases were detected at the Ni3N/Si interface These findings demonstrate the dissociation of Ni3N under ion bombardment and the competition of chemical driving forces and collision cascade mixing at the interface more

Topics: Ion beam mixing (67%), Ion implantation (60%), Collision cascade (57%) more

Journal ArticleDOI: 10.1016/J.SURFREP.2010.11.001
I.P. Jain1, Garima Agarwal1Institutions (1)
Abstract: The injection of material into a target specimen in the form of an accelerated ion beam offers a most valuable tool for altering its physical, chemical, structural, surface and interface properties in a controlled manner and tailoring new materials for basic and applied research for science and technology. The present review describes experimental, theoretical and recent aspects of ion beam modifications at various solids, thin films, and multilayered systems covering wider energy ranges including the older basic concepts which are now of interest. These results reveal that the ion–solid interaction physics provides a unique way for controlling the produced defects of the desired type at a desired location. These interests have been stimulated by the possibilities of synthesizing novel materials with potential applications in the field of thin films, surfaces and interface science. Many applications of ion induced engineering are being developed for various sciences of high technological interest for future aspects. more

Topics: Ion beam (56%)

215 Citations

Journal ArticleDOI: 10.1088/0022-3727/34/14/305
Abstract: Knowledge on the thickness, composition, and interfaces of thin films and multilayers is, in many systems, fundamental for the understanding and optimization of their properties. One of the techniques often applied to such studies is Rutherford backscattering (RBS). However, it has been very difficult to account for the effects of interface roughness in the data obtained, and the alternative has been to develop dedicated data analysis codes for particular problems where roughness plays a determinant role. In this work, the effect of roughness is taken into account in the data analysis by calculating the effect of roughness on the apparent energy resolution as a function of depth. This depends on the exact type of roughness, and three different models have been implemented: inhomogeneous layer thickness, corrugated sample, and rough substrate surface. Interfacial mixing in multilayers can also be analysed with the method developed. Automatic fits to the data can be performed in this way, where the roughness parameters are derived during the fit, providing a new tool for RBS analysis. The code is applied to several systems in order to test its validity and applicability. Systems which are hard to analyse by RBS have been chosen: Si/VS/ Si0.65 Ge0.35 300 nm/ Si0.2 Ge0.8 4 nm/ Si0.65 Ge0.35 15 nm/Si 3 nm thin films, where VS stands for a linearly composition-graded virtual substrate; and MgO /( Fe 25 A/ Co 20 A)10 multilayers. more

Topics: Surface finish (53%)

57 Citations

Journal ArticleDOI: 10.1142/S0217984901003196
N.P. Barradas1, A. D. Sequeira1, N. Franco1, Maksym Myronov2  +3 moreInstitutions (2)
Abstract: The growth of Si1-xGex quantum wells with high Ge composition (x>0.5) on Si(001) substrates by MBE is of great interest both for HMOS device applications and fundamental research. One of the possibilities to obtain a high Ge content Si1-xGex channel for mobile carriers, while retaining its strain, is to grow a relaxed Si1-yGey buffer layer on an underlying Si substrate. Such a buffer is termed a virtual substrate (VS), which is a constituent of SiGe metamorphic heterostructures. The effect of annealing on the structure of the Si(001)/VS/Si0.7Ge0.3/Si0.2Ge0.8/Si0.7Ge0.3 heterostructures was studied by grazing angle of incidence RBS. The thickness of the Si0.2Ge0.8 channel is inhomogeneous, which makes the analysis of the data by traditional means very hard. We have developed a model whereby the influence of the thickness inhomogeneity of each layer in the apparent energy resolution as a function of depth can be calculated. Automatic fits to the data were performed, and the roughness parameters, that is, the standard deviation of the thickness inhomogeneity of the relevant layers, were obtained, together with the thickness and stoichiometry of each layer. The results are compared with TEM and high resolution XRD experiments. more

Topics: Heterojunction (51%)

52 Citations

Journal ArticleDOI: 10.1016/S0168-583X(01)01202-2
N.P. Barradas1Institutions (1)
Abstract: In this work automated fitting of Rutherford backscattering (RBS) data including the effect of roughness is performed, by calculating the effect of roughness on the apparent energy resolution as a function of depth. This depends on the exact type of roughness, and three different models have been implemented: inhomogeneous layer thickness, corrugated sample, and rough substrate surface. Full automated fitting can be performed including one, or more, of the models, with the roughness parameters (e.g. standard deviation of the thickness of any number of layers), as well as the sample structure, as fitting parameters. The code is applied to the system substrate/Re 50 A/(Co 20 A/Re 5 A)16, which had been studied before by other methods. The results are excellent, providing a new tool for RBS data analysis. more

Topics: Surface finish (52%)

24 Citations

Journal ArticleDOI: 10.1016/J.VACUUM.2009.06.003
Renu Dhunna1, Chhagan Lal1, D.K. Avasthi, Sudipto Roy Barman  +2 moreInstitutions (1)
11 Aug 2009-Vacuum
Abstract: The irradiation effect in Ni 3 N/Si bilayers induced by 100 MeV Au ions at fluence 1.5 × 10 14 ions/cm 2 was investigated at room temperature. Grazing incidence X-ray diffraction determined the formation of Ni 2 Si and Si 3 N 4 phases at the interface. The roughness of the thin film was measured by atomic force microscopy. X-ray reflectivity was used to measure the thickness of thin films. X-ray photoelectron spectroscopy has provided the elemental binding energy of Ni 3 N thin films. It was observed that after irradiation (Ni 2p 3/2 ) peak shifted towards a lower binding energy. Optical properties of nickel nitride films, which were deposited onto Si (100) by ion beam sputtering at vacuum 1.2 × 10 −4 torr, were examined using Au ions. In-situ I – V measurements on Ni 3 N/Si samples were also undertaken at room temperature which showed that there is an increase in current after irradiation. more

Topics: X-ray photoelectron spectroscopy (55%), Thin film (53%), Irradiation (52%) more

12 Citations


Open accessBook
J.P. Biersack, James F. Ziegler1Institutions (1)
01 Aug 1985-
Abstract: The stopping and range of ions in matter is physically very complex, and there are few simple approximations which are accurate. However, if modern calculations are performed, the ion distributions can be calculated with good accuracy, typically better than 10%. This review will be in several sections: a) A brief exposition of what can be determined by modern calculations. b) A review of existing widely-cited tables of ion stopping and ranges. c) A review of the calculation of accurate ion stopping powers. more

9,987 Citations

Journal ArticleDOI: 10.1016/0168-583X(85)90762-1
Lawrence Doolittle1Institutions (1)
Abstract: A computer program which simulates Rutherford backscattering spectra is currently in use at Cornell University and other institutions. Straggling and detector resolution are among the effects included. Samples are considered to be made up of a finite number of layers, each with uniform composition. The emphasis in the mathematics is on accuracy beyond that of iterated surface approximation methods. Thicker layers can thus be analyzed without a net loss in accuracy. The mathematical description of the sample can then have fewer layers and fewer calculations are required. This paper provides estimates of the number of arithmetic operations used by the program for any simulation to demonstrate the tradeoffs between accuracy, computation time, and algorithm sophistication. more

2,510 Citations

Journal ArticleDOI: 10.1016/0029-554X(81)90668-6
Peter Sigmund1, A. Gras-Marti1Institutions (1)
Abstract: Collisional mixing by ion bombardment of dilute impurities in homogeneous matrices is treated theoretically. Relocation profiles are determined explicitly for ion-impurity knockon events (recoil implantation) as well as isotropic cascade mixing. Mean shifts and variances are evaluated for anisotropic cascade mixing. Both matrix and impurity knockon events are taken into account. Widely different fluence dependencies are found for the calculated half-widths of relocation profiles for different mechanisms, while the variance, when defined at all, is always proportional to fluence. Recoil implantation may give rise to a considerable mean shift of an impurity marker, but causes negligible peak shift up to quite high fluences. Isotropic cascade mixing receives a substantial contribution from recoils with energy far above threshold; this contribution is increasingly important with increasing fluence. Matrix relocation dominates measurable mixing profiles for heavy impurities in light matrices, while impurity relocation dominates in the opposite case. A Pt marker in Si bombarded by 300 keV Xe, is shown to move toward the surface with a mean rate comparable to the rate of surface erosion due to sputtering. The spread due to matrix relocation in this system is shown to exceed the spread due to impurity relocation by a factor of ∼ 20 and turns out to be in good agreement with experimental results. more

Topics: Mixing (physics) (51%)

431 Citations

Journal ArticleDOI: 10.1016/0168-583X(85)90688-3
M. Uhrmacher1, K. Pampus1, F. J. Bergmeister1, D. Purschke1  +1 moreInstitutions (1)
Abstract: Gamma ray yield functions of (p, αγ) and (p, γ) resonance reactions on semi-thick 19F, 23Na, 24,26Mg and 27Al targets were measured and used to calibrate the accelerating voltage and energy resolution of the new 500 kV heavy ion implanter at Gottingen. The energy spread of the proton beam was found to vary linearly with the accelerating voltage from ΔE(200 keV) = 55 eV fwhm to ΔE(500 keV) = 105 eV; it is made up by a 0.012% high voltage ripple and the Doppler broadening of the resonances due to the thermal motion of the target nuclei. A long term stability of the proton energy of Applications of the accelerator for the remeasurement of some resonance energies and widths and for depth profiling of light implanted ions in metals by the resonance broadening method will be briefly discussed. more

Topics: Doppler broadening (56%), Acceleration voltage (53%), Resonance (51%) more

291 Citations

Journal ArticleDOI: 10.1016/S0920-2307(05)80007-6
Yang-Tse Cheng1Institutions (1)
Abstract: A thermodynamic approach to atomic diffusion in a thermal spike is reviewed. The approach is based on recent ion mixing experiments which demonstrate the influence of the heat of mixing and the cohesive energy of solids on ion mixing. These thermodynamic effects are assimilated into a phenomenological model of ion mixing. The model is generalized to low-energy ion mixing during sputter depth profiling and is used to elucidate the nature of atomic diffusion in a thermal spike. The onset of radiation-enhanced diffusion in ion mixing is also discussed. A fractal geometry approach to spike formation is presented. An “idealized” collision cascade constructed from the inverse-power potential V(r) ∝ r−1/m (0 more

Topics: Collision cascade (56%), Ion (53%), Diffusion (business) (53%) more

224 Citations

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