共查询到20条相似文献,搜索用时 15 毫秒
1.
Silvia Richter Matthias Bückins Anke Aretz Stepan Kyrsta Michael Spähn Joachim Mayer 《Mikrochimica acta》2004,145(1-4):187-192
Electron probe microanalysis (EPMA) offers high sensitivity and high accuracy in quantitative measurements of chemical compositions and mass coverages. Owing to the low detection limits of the wavelength-dispersive technique, monolayers with mass coverages of about 0.05µgcm–2 can be detected. Assuming a density of 5gcm–3 this corresponds to a thickness of 0.1nm. With these advantages in mind, EPMA was extended to depth profile analysis in the sub-micron range using a surface removal technique.The present paper shows how depth profile analysis can be improved by combining EPMA and the focused ion beam (FIB) technique. The focused ion beam system uses a Ga+ ion beam. The ion beam allows the milling of defined geometries on the nanometer scale, so that very shallow bevels with exactly defined angles in relation to the surface can be obtained. Low surface damage is expected due to low sputtering effects. Calibrated WDX measurements along the bevel deliver quantitative concentration depth profiles. First results obtained with this new combination of methods will be presented for a multilayered sample used in optical data storage. 相似文献
2.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1997,52(7):813-821
The application of ion beam sputtering in combination with glancing-incidence X-ray fluorescence spectrometry for high-resolution concentration depth profiling is presented. Two new techniques are described: first, in the “bevel-etching technique”, the sample depth profile is uncovered on the sample surface either by sputter etching with a gradient of the ion beam intensity or by varying the sputtering time by moving a shutter in front of the sample; second, in the “deposition technique”, samples are etched uniformly and the sputtered material is deposited on a moving substrate. The bevelled sample and also the material deposited on the substrate are characterized (laterally resolved) by glancing incidence X-ray fluorescence spectrometry. The apparatus and techniques are described in detail. Typical experiments showing the advantages of and problems with the two techniques are discussed. The achievable depth resolutions, 1.5 nm with the bevel-etching technique and 1.4 nm with the deposition technique, are comparable with the best results from other depth profiling methods. 相似文献
3.
Sputter depth profiling of organic films while maintaining the molecular integrity of the sample has long been deemed impossible
because of the accumulation of ion bombardment-induced chemical damage. Only recently, it was found that this problem can
be greatly reduced if cluster ion beams are used for sputter erosion. For organic samples, carbon cluster ions appear to be
particularly well suited for such a task. Analysis of available data reveals that a projectile appears to be more effective
as the number of carbon atoms in the cluster is increased, leaving fullerene ions as the most promising candidates to date.
Using a commercially available, highly focused C60q+ cluster ion beam, we demonstrate the versatility of the technique for depth profiling various organic films deposited on
a silicon substrate and elucidate the dependence of the results on properties such as projectile ion impact energy and angle,
and sample temperature. Moreover, examples are shown where the technique is applied to organic multilayer structures in order
to investigate the depth resolution across film-film interfaces. These model experiments allow collection of valuable information
on how cluster impact molecular depth profiling works and how to understand and optimize the depth resolution achieved using
this technique. 相似文献
4.
J. Papadakis G. S. Fanourgakis S. C. Farantos M. Founargiotakis 《Journal of computational chemistry》1997,18(8):1011-1022
The most robust numerical algorithms for unconstrained optimization that involve a line search are tested in the problem of locating stable structures and transition states of atomic microclusters. Specifically, the popular quenching technique is compared with conjugate gradient and variable metric algorithms in the Mg+Arn clusters. It is found that the variable metric method BFGS combined with an approximate line minimization routine is the most efficient, and it shows global convergence properties. This technique is applied to find a few hundred stationary points of Mg+Ar12 and to locate isomerization paths between the two most stable icosahedral structures found for Mg+Ar12. The latter correspond to a solvated and a nonsolvated ion, respectively. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 :1011–1022, 1997 相似文献
5.
Lin WC Liu CP Kuo CH Chang HY Chang CJ Hsieh TH Lee SH You YW Kao WL Yen GJ Huang CC Shyue JJ 《The Analyst》2011,136(5):941-946
Cluster ion sputtering has been proven to be an effective technique for depth profiling of organic materials. In particular, C(60)(+) ion beams are widely used to profile soft matter. The limitation of carbon deposition associated with C(60)(+) sputtering can be alleviated by concurrently using a low-energy Ar(+) beam. In this work, the role of this auxiliary atomic ion beam was examined by using an apparatus that could analyze the sputtered materials and the remaining target simultaneously using secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectrometry (XPS), respectively. It was found that the auxiliary 0.2 kV Ar(+) stream was capable of slowly removing the carbon deposition and suppresses the carbon from implantation. As a result, a more steady sputtering condition was achieved more quickly with co-sputtering than by using C(60)(+) alone. Additionally, the Ar(+) beam was found to interfere with the C(60)(+) beam and may lower the overall sputtering rate and secondary ion intensity in some cases. Therefore, the current of this auxiliary ion beam needs to be carefully optimized for successful depth profiling. 相似文献
6.
H. M. Moore David Roberts Michael Harriott D. Thorburn Burns 《Fresenius' Journal of Analytical Chemistry》1997,358(5):652-655
Levels of cadmium, copper, aluminium, iron, manganese and zinc (Cd, Cu, Al, Fe, Mn and Zn) in deep-sea sediments and sediment-feeding
holothurians are reported. Profiles of metals were found to vary with depth in the sediment. Holothurian foregut metal values
are generally closer to surficial sediment levels, whereas body wall levels, with the exception of Cd and Cu, were generally
lower. Holothurians are presented as potential biomonitors of metal concentrations in the deep-sea floor environment.
Received: 21 October 1996/Revised: 3 January 1997/Accepted: 7 January 1997 相似文献
7.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1995,50(3):265-270
Experiments using a combination of laterally resolved glancing incidence X-ray fluorescence spectrometry in the vicinity of the critical angle of total reflection and ion beam ramp etching were performed to work out a new technique for depth profiling in solid-state thin films with nanometre resolution. The lateral point-to-point resolution of the total-reflection X-ray fluorescence (TXRF) spectrometer used was determined as 200 ± 10 μm by means of standard samples (Cr bars on Si). At an inclination angle in the range of 10−4 degrees for the ramp, which has been produced by ion beam etching, the geometrically covered depth is in the range of 1 nm. In order to demonstrate the potential of the new technique, preliminary results on Cu/Cr multilayers on Si substrate are presented. 相似文献
8.
Solid state phase epitaxy (SSPE) by rapid thermal processing (RTP) of Co/Ti double layers deposited on (100)-Si substrates is a common technique for the production of buried CoSi2-silicide conducting layers for microelectronics technology. The understanding of the processes during the SSPE silicide formation on the atomic scale needs the study of the elemental depth distributions with nanometer scale depth resolution of all multi-layer elemental constituents at different RTP conditions. A new experimental technique, the laterally resolved TXRF analysis line scan method across the bevelled section of the sample prepared by ex-situ ion beam sputter etching, was used to obtain the multi-element depth profiles. First results on the as evaporated Co/Ti (30 nm thick) double layer system prior to the RTP and on the final CoSi2/TixCoySiz-system (160 nm thickness) after the RTP were obtained. 相似文献
9.
Summary The following methods for the determination of crater depths have been tested in the case of local and thin film analysis by spark and laser mass spectroscopy: stylus technique, refocussing of optical microscope, optical interference microscopy, oblique observation by a scanning electron microscope in connection with contamination lines or with ion beam slope cutting, weighing technique, determination of the concentration of a monitoring element having a well known depth profile.The methods mentioned complete each other in the depth interval from 0.01 to 100 m and with regard to their usefulness for local craters and scanned areas. The weighing technique is less useful because of the very low mass losses during the analysis. As a rule, depth resolution as well as accuracy of the measuring data are limited by the roughness of the crater bottom and/or by systemactic errors in the application of the measuring techniques. The results are also applicable to optical emission spectral analysis with excitation by spark, laser beam or glow discharge, as well as to dynamic SIMS. 相似文献
10.
Silicon carbide thin films, prepared by carbonization of Si-wafers are analysed by Auger depth profiling. The influence of atomic mixing is simulated with a Monte Carlo model. By using mixing simulations the dependence of the two mixing parameters (width of the mixing zone and recoil depth) on ion beam energy, incidence angle and ion mass can be calculated. For comparison of the simulated data with Auger measurements an Auger electron escape depth correction is necessary. The simulated and -corrected data of several layer structures show good qualitative agreement with Auger depth profiles of thin carbonized SiC-layers.Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday 相似文献
11.
Pavel Andreevich Yunin Yurii Nikolaevich Drozdov Mikhail Nikolaevich Drozdov 《Surface and interface analysis : SIA》2015,47(7):771-776
We propose a new approach to express SIMS depth profiling on a TOF.SIMS‐5 time‐of‐flight mass spectrometer. The approach is based on the instrument capability to independently perform raster scans of sputter and probe ion beams. The probed area can be much smaller than the diameter of a sputter ion beam, like in the AES depth profiling method. This circumstance alleviates limitations on the sputter beam–raster size relation, which are critical in other types of SIMS, and enables analysis on a curved‐bottomed sputter crater. By considerably reducing the raster size, it is possible to increase the depth profiling speed by an order of magnitude without radically degrading the depth resolution. A technique is proposed for successive improvement of depth resolution through profile recovery with account for the developing curvature of the sputtered crater bottom in the probed area. Experimental study of the crater bottom form resulted in implementing a method to include contribution of the instrumental artifacts in a nonstationary depth resolution function within the Hofmann's mixing–roughness–information depth model. The real‐structure experiment has shown that the analysis technique combining reduction of a raster size with a successive nonstationary recovery ensures high speed of profiling at ~100 µm/h while maintaining the depth resolution of about 30 nm at a 5 µm depth. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
12.
You YW Chang HY Lin WC Kuo CH Lee SH Kao WL Yen GJ Chang CJ Liu CP Huang CC Liao HY Shyue JJ 《Rapid communications in mass spectrometry : RCM》2011,25(19):2897-2904
Dynamic secondary ion mass spectrometry (D-SIMS) analysis of poly(ethylene terephthalate) (PET) and poly(methyl methacrylate) (PMMA) was conducted using a quadrupole mass analyzer with various combinations of continuous C(60)(+) and Ar(+) ion sputtering. Individually, the Ar(+) beam failed to generate fragments above m/z 200, and the C(60)(+) beam generated molecular fragments of m/z ~1000. By combining the two beams, the auxiliary Ar(+) beam, which is proposed to suppress carbon deposition due to C(60)(+) bombardment and/or remove graphitized polymer, the sputtering range of the C(60)(+) beam is extended. Another advantage of this technique is that the high sputtering rate and associated high molecular ion intensity of the C(60)(+) beam generate adequate high-mass fragments that mask the damage from the Ar(+) beam. As a result, fragments at m/z ~900 can be clearly observed. As a depth-profiling tool, the single C(60)(+) beam cannot reach a steady state for either PET or PMMA at high ion fluence, and the intensity of the molecular fragments produced by the beam decreases with increasing C(60)(+) fluence. As a result, the single C(60)(+) beam is suitable for profiling surface layers with limited thickness. With C(60)(+)-Ar(+) co-sputtering, although the initial drop in intensity is more significant than with single C(60)(+) ionization because of the damage introduced by the auxiliary Ar(+), the intensity levels indicate that a more steady-state process can be achieved. In addition, the secondary ion intensity at high fluence is higher with co-sputtering. As a result, the sputtered depth is enhanced with co-sputtering and the technique is suitable for profiling thick layers. Furthermore, co-sputtering yields a smoother surface than single C(60)(+) sputtering. 相似文献
13.
U. Zastrow R. Loo K. Szot J. Moers T. Grabolla D. Behammer L. Vescan 《Analytical and bioanalytical chemistry》1997,358(1-2):203-207
SIMS depth profiling during O2
+ bombardment has been performed to analyse epitaxially grown Si p-n-p layers, which define the p-channel region in vertical
Si-p MOS transistors, as well as to establish “on-chip” depth profiling of the functional vertical device. The SIMS detection
limit of 31P in Si, phosphorus used as n-type dopant in the transistor, has been optimised as a function of the residual gas pressure
in the SIMS analysis chamber and of the sputter erosion rate. We demonstrate that good vacuum during SIMS analysis combined
with high erosion rates allows the simultaneous quantitative SIMS depth profiling of n- and p-type dopant concentrations in
the vertical transistor. Small area “on-chip” SIMS depth profiling through the layered structure of Al-contact/TiSi2/Si(p-n-p)/Si-substrate has been performed. Factors influencing the depth resolution during “on-chip” analysis of the transistor
are discussed especially in terms of sputtering induced ripple formation at the erosion crater bottom, which has been imaged
with atomic force microscopy.
Received: 15 August 1996 / Revised: 17 January 1997 / Accepted: 21 January 1997 相似文献
14.
A commercial particle beam interface coupled to a single quadrupole mass spectrometer has been used for a nontarget screening
of highly contaminated water samples from a former gas plant. A liquid chromatographic system has been used to separate hydrophilic
compounds with a high percentage water gradient without any loss of efficiency in the MS interface. The ground water showed
a high pollution burden in the total ion current chromatogram. Full scan EI mass spectra have been obtained for identification
of unknown compounds which could be assigned to oxidation products of heterocyclic aromatic compounds, some known constituents
of coal tar. The identification of 6(5H)-phenanthridinone has been confirmed by comparison with a corresponding standard.
The difficulties of an unequivocal identification of isoquinolinone and methyl derivatives of quinolinone based on their EI
mass spectra are discussed.
Received: 7 March 1997 / Revised: 15 May 1997 / Accepted: 22 May 1997 相似文献
15.
A commercial particle beam interface coupled to a single quadrupole mass spectrometer has been used for a nontarget screening
of highly contaminated water samples from a former gas plant. A liquid chromatographic system has been used to separate hydrophilic
compounds with a high percentage water gradient without any loss of efficiency in the MS interface. The ground water showed
a high pollution burden in the total ion current chromatogram. Full scan EI mass spectra have been obtained for identification
of unknown compounds which could be assigned to oxidation products of heterocyclic aromatic compounds, some known constituents
of coal tar. The identification of 6(5H)-phenanthridinone has been confirmed by comparison with a corresponding standard.
The difficulties of an unequivocal identification of isoquinolinone and methyl derivatives of quinolinone based on their EI
mass spectra are discussed.
Received: 7 March 1997 / Revised: 15 May 1997 / Accepted: 22 May 1997 相似文献
16.
Giovanni Ceccio Jiri Vacik Pavel Horák Antonino Cannavò Vladimir Hnatowicz 《Surface and interface analysis : SIA》2020,52(12):939-942
Diffusion of Li ions in thin sandwich films with copper or lead encompassing layers (obtained by ion beam sputtering deposition technique) has been studied. These metals are promising candidates for electrodes in lithium-ion batteries. It is because they exhibit an ability to store and release Li ions during charging and discharging processes. Lithium diffusion was induced in samples by thermal annealing cycles. The lithium depth profile was measured using a nondestructive neutron depth profiling technique after each thermal annealing step. The analysis of experimental data allowed to evaluate the lithium depth profiles and directly calculate the diffusion coefficients. 相似文献
17.
The possibilities of measuring depth profiles by secondary ion mass spectrometry are evaluated. The influence of different instrumental and experimental parameters on depth resolution in the profiles are studied: the effects of primary ion beam characteristics, reactive gas adsorption and mechanical aperturing in secondary ion extraction are discussed. Beam effects are studied from the point of view of surface damage. The effects of secondary processes, such as crater edge effects, element mixing, preferential sputtering, background signals, (residual) gas contamination and ion-induced topographical and compositional changes are studied for thin metal and binary materials. 相似文献
18.
A novel experimental method for the assessment of the escape probability of photoelectrons as a function of depth and their
mean escape depths is described and illustrated for photoelectrons leaving an aluminium oxide surface. The results are compared
with those of the straight line approximation model calculations.
Received: 30 July 1997 / Revised: 7 April 1998 / Accepted: 8 April 1998 相似文献
19.
We attempted to make an accurate depth profiling in secondary ion mass spectrometry (SIMS) including backside SIMS for ultra‐thin nanometer order layer. The depth profiles for HfO2 layers that were 3 and 5 nm thick in a‐Si/HfO2/Si were measured using quadrupole and magnetic sector type SIMS instruments. The depth profiling for an ultra‐thin layer with a high depth resolution strongly depends on how the crater‐edge and knock‐on effects can be properly reduced. Therefore, it is important to control the analyzing conditions, such as the primary ion energy, the beam focusing size, the incidence angle, the rastered area, and detected area to reduce these effects. The crater‐edge effect was significantly reduced by fabricating the sample into a mesa‐shaped structure using a photolithography technique. The knock‐on effect will be serious when the depth of the layer of interest from the surface is located within the depth of the ion mixing region due to the penetration of the primary ions. Finally, we were able to separately assign the origin of the distortion to the crater‐edge effect and knock‐on effect. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
20.
A mobile and easily practicable microsampling technique for historical glasses and its application is presented. About 100
μg of material is scraped off the object with a fine grinding file. The analysis of main, minor and trace elements in the
digested sample is performed by IC, GFAAS and FIA with photometric detection. The procedure has been verified by measurements
of standard glasses. Investigations of baroque ruby glasses showed the suitability of the microsampling technique for archaeometrical
application.
Received: 6 January 1997 / Revised: 17 March 1997 / Accepted: 25 March 1997 相似文献