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Micropatterning of living single cells and cell clusters over millimeter-centimeter scale areas is of high demand in the development of cell-based biosensors. Micropatterning methodologies require both a suitable biomimetic support and a printing technology. In this work, we present the micropatterning of living mammalian cells on carboxymethyl dextran (CMD) hydrogel layers using the FluidFM BOT technology. In contrast to the ultrathin (few nanometers thick in the dry state) CMD films generally used in label-free biosensor applications, we developed CMD layers with thicknesses of several tens of nanometers in order to provide support for the controlled adhesion of living cells. The fabrication method and detailed characterization of the CMD layers are also described. The antifouling ability of the CMD surfaces is demonstrated by in situ optical waveguide lightmode spectroscopy measurements using serum modeling proteins with different electrostatic properties and molecular weights. Cell micropatterning on the CMD surface was obtained by printing cell adhesion mediating cRGDfK peptide molecules (cyclo(Arg-Gly-Asp-d-Phe-Lys)) directly from aqueous solution using microchanneled cantilevers with subsequent incubation of the printed surfaces in the living cell culture. Uniquely, we present cell patterns with different geometries (spot, line, and grid arrays) covering both micrometer and millimeter-centimeter scale areas. The adhered patterns were analyzed by phase contrast microscopy and the adhesion process on the patterns was real-time monitored by digital holographic microscopy, enabling to quantify the survival and migration of cells on the printed cRGDfK arrays.

CoCrFeMnNi multi-principal element alloy films were grown by direct current magnetron sputtering in a mixture of argon and air. The air fraction was varied from 4 to 50%, which resulted in a change of the phase state of the growing film. A 〈100〉 preferred orientation face centered cubic metal (doped with O and N) structure develops below 12% of air. Between 12 and 30% air, a two phase 〈100〉 preferred orientation face centered cubic metal + oxynitride (B1) structure forms. Above 30% of air a single phase B1 oxynitride structure is observed. Compared to nitrogen, oxygen is preferentially incorporated into the growing structures. The 〈100〉 preferential orientation is the result of selective nucleation (below 30% of air) or competing growth (above 30% of air) of the forming crystals. Detailed microscopic analysis shows a complex structure for both the metal and the oxynitride phase in the films deposited at low and high air fraction. In both cases, the films are characterized by local structures ordered on a few nanometer scale and their formation is explained as a result of spinodal decomposition of the as-formed homogenous structure which occurs during film growth.

Optical properties of Zr and its oxide have been measured on the surface of nuclear fuel cladding tubes. It has been shown that ellipsometry with focusing can routinely be used to measure thin layers and surface properties on Zr tubes with a diameter as small as 9.1 mm. Multi-sample and depth profiling models have been used to determine reference dielectric function spectra for both the Zr substrate and its oxide. Temporal behavior of the oxide thickness has been measured for oxidation temperatures of 600 °C and 800 °C. A vertical inhomogeneity of the oxide properties has been found by the optical measurements as well as by depth-profiling X-ray photoelectron spectroscopy investigations that revealed the formation of sub-oxides at the interface region of Zr and its surface oxide.

Surface coatings of the polysaccharide dextran and its derivatives are key ingredients especially in label-free biosensors for the suppression of non-specific binding and for receptor immobilization. Nevertheless, the nanostructure of these ultrathin coatings and its tailoring by the variation of the preparation conditions have not been profoundly characterized and understood. In this work carboxymethylated dextran (CMD) was prepared and used for fabricating ultrathin surface coatings. A grafting method based on covalent coupling to aminosilane- and epoxysilane-functionalized surfaces was applied to obtain thin CMD layers. The carboxyl moiety of the CMD was coupled to the aminated surface by EDC-NHS reagents, while CMD coupling through epoxysilane molecules was performed without any additional reagents. The surface analysis following the grafting procedures consisted of X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared spectroscopy (ATR-IR), spectroscopic ellipsometry, atomic force microscopy (AFM) and optical waveguide lightmode spectroscopy (OWLS). The XPS and AFM measurements showed that the grafting resulted in a very thin dextran layer of a few nanometers. The OWLS method allowed devising the structure of the interfacial dextran layers by the evaluation of the optogeometrical parameters. The alteration in the nanostructure of the CMD layer with the chemical composition of the silane coverage and the pH of the grafting solution was revealed by in situ OWLS, specifically, lain down chains were found to be prevalent on the surface under neutral and basic conditions on epoxysilylated surfaces. The developed methodologies allowed to design and fabricate nanometer scale CMD layers with well-controlled surface structure, which are very difficult to characterize in aqueous environments using present instrumentations and highly hydrated surface layers.

TiC/amorphous carbon (TiC/a:C) nanocomposite thin films were deposited from two targets by direct current (DC) magnetron sputtering system at room temperature. The film's composition and morphology were studied in detail by High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction (SAED), X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. The sputtering power of carbon target (P C ) was kept at the constant 150 W, while the sputtering power of titanium target (P Ti ) was changed between 5 W and 150 W. Additionally, a C/Ti multilayer was deposited and characterized for comparison. The growth mechanism was derived from the XPS, Raman and HRTEM observations on the grown layer structures and it was completed by a semi-empirical equation for the dependence on the average atomic fraction of Ti. The HRTEM investigations confirmed that the first nucleating phase is amorphous carbon due to its lowest surface energy among the possible phases. The second nucleating phase within the amorphous carbon matrix is TiC; its growth is kinetically not limited. The increase of Ti content resulted in larger TiC nanocrystallites and thinner amorphous carbon spacing between the TiC phases shown by HRTEM analysis. The characteristic texture of the crystallite structure was observed in the case of 120 W and 150 W of P Ti . All observation confirmed the two main phases; amorphous carbon + carbide phase. The hcp titanium phase was not formed due to nucleation barrier. The average sputtered composition differs from the average deposited composition due to different nucleation barriers of different phases.

Ion irradiation of interfaces causes intermixing of the adjacent regions, which leads to compound formation in certain cases. With the aim of building, some nm thick protective coating at ambient temperature, C/Si/C/Si/C/Si substrate samples were irradiated with Ar + , Xe + , and Ga + ions in the energy and fluence ranges of 20–200 keV and 1–3 × 10 16 ion cm − 2 , respectively. The effect of ion irradiation was studied by Auger electron spectroscopy depth profiling and cross sectional transmission electron microscopy. All ion irradiations produced SiC rich regions the thickness of which, being some nm, could be tailored by changing the ion irradiation conditions. The chemical resistance of the SiC rich layer has been tested by polysilicon etchant. Rutherford Backscattering Spectrometry (RBS) analysis showed that etching rate of the SiC rich region was orders of magnitude lower than that of polysilicon on the whole irradiated area. It was also shown that Transport of Ions in Dynamic (TRIDYN) simulation combined with a simple compound formation rule provides a fair description of the resultant SiC distributions. Thus, it is possible to design and fabricate wafer-scale SiC for a given sample architecture by “TRIDYN simulation assisted” ion irradiation.

30 keV Ga + implantation was applied to a nominally C(20 nm)/Si(20 nm)/C(20 nm)/Si(20 nm)/C(20 nm)/Si substrate multilayer system. Due to the irradiation intermixing occurred and a layer containing C, Si, Ga and (amorphous) SiC was obtained. The thickness (7–30 nm) and composition of the layer depended on the fluence of irradiation. The chemical resistance of the layer was tested by applying microwave oxidation and various polysilicon etchants and was found to be excellent if the SiC concentration was above 20%. Using an etchant with an etching rate of about 100 nm/s for poly-Si during 10 s had not affected the integrity of the intermixed region with a thickness of 10 nm; only some defects appeared. With a further increase of the etching time the size of defects increased resulting in inhomogeneous layer removal. The in-depth composition of non-defective region that remained on the surface was determined by AES depth profiling, which revealed that the intermixed layer did not change during the harsh etching except the removal of its thin surface layer containing less than 20% SiC. The etching rate of the intermixed layer is orders of magnitude lower than that for poly-Si.

Published results of the multitudinous experiments studying the relationships between the properties and process parameters of sputter deposited TiN films indicate a very complex problem. The complexity manifests itself preferentially in the sporadic formation of the and preferred orientation (PO) and in the sequential formation (crossover) of the and PO in thicker films, even when the deposition parameters are maintained constant during the deposition. The first problem has been clarified by dedicated experiments as well as theoretical works. These revealed that the selection between the development of the and PO is related to the condition of the impinging species, i.e. whether they are neutral or ionized, molecular or atomic Ti and N species, to the degree of ionization, to the ratio of the impinging rates of these species and to their energy as well. Understanding the cross-over formation between the and PO remained, however, an open question so far. As the driving force for this process, the operation of the proposed overall energy minimisation effect, the interplay of the surface and interface and the inner stress energy during thickness growth of the film has been queried. In the present work authors point out that the complex structural and micro-chemical analysis of the cross-sectional specimens of TiN thin films with PO crossover could provide the fundamental information required to discover the possible phenomena governing the evolution of this particular structure and to reconstruct its pathway. That is demonstrated for the situation when the origin of the to PO crossover could be related to the contamination effect, caused by gas desorption at starting the deposition. In the discussed experiment the TiN film is doped by oxygen and the oxygen concentration changing from 18 to 11 at.% during the deposition.

Focused ion beam (FIB)-induced ion mixing was studied in a C/Si/C/Si/C/Si substrate multilayer structure sample by means of Auger electron spectroscopy (AES) depth profiling, and transmission electron microscopy (TEM). The multilayer sample was irradiated with Ga+ ions using focused ion beam (FIB) at room temperature. The ion energy and fluence of the ion irradiation varied in the range of 10–30 keV and 10–120 × 1015 ions/cm2, respectively. The ion irradiation induced a slightly asymmetric intermixing of the top C and Si layers, which could be modeled by the TRIDYN code. During ion mixing, part of the intermixed C and Si atoms reacted, forming amorphous SiC. The amount of SiC depends on the square root of the Ga+ fluence. Thus, amorphous SiC thin film (with Ga contamination) with thickness in the nanometer range can be produced by means of FIB.

Ion-beam mixing in C/Ta layered systems was investigated. C 8 nm/Ta 12 nm and C 20 nm/Ta 19 nm/C 20 nm layer systems were irradiated by Ga + ions of energy in the range of 2–30 keV. In case of the 8 nm and 20 nm thick C cover layers applying 5–8 keV and 20–30 keV Ga + ion energy, respectively resulted in strongly asymmetric ion mixing; the carbon was readily transported to the Ta layer, while the reverse process was much weaker. Because of the asymmetrical transport the C/TaC interface remained sharp independently from the applied fluence. The carbon transported to the Ta layer formed TaC x . The stoichiometry of the carbide produced varied along the depth. The TaC x layer contained implanted Ga, the concentration of which decreased with increasing depth. The thickness of the TaC x layer could be tailored by the ion fluence and energy making possible to produce coating layer of desired thickness.

The relative sputtering yield of carbon with respect to tantalum was determined for 1 keV Ar + ion bombardment in the angular range of 70°―82° (measured from surface normal) by means of Auger electron spectroscopy depth profiling of C/Ta and Ta/C bilayers. The ion bombardment-induced interface broadening was strongly different for the C/Ta and Ta/C, whereas the C/Ta interface was found to be rather sharp, the Ta/C interface was unusually broad. Still the relative sputtering yields (Y C /Y Ta ) derived from the Auger electron spectroscopy depth profiles of the two specimens agreed well. The relative sputtering yields obtained were different from those determined earlier on thick layers, calculated by simulation of SRIM2006 and by the fitting equation of Eckstein. The difference increases with increase of angle of incidence.

In elastic peak electron spectroscopy (EPES), the nearest vicinity of elastic peak in the low kinetic energy region reflects electron inelastic and quasielastic processes. Incident electrons produce surface excitations, inducing surface plasmons, with the corresponding loss peaks separated by 1–20 eV energy from the elastic peak. In this work, X-ray photoelectron spectroscopy (XPS) and helium pycnometry are applied for determining surface atomic composition and bulk density, whereas atomic force microscopy (AFM) is applied for determining surface morphology and roughness. The component due to electron recoil on hydrogen atoms can be observed in EPES spectra for selected primary electron energies. Simulations of EPES predict a larger contribution of the hydrogen component than observed experimentally, where hydrogen deficiency is observed. Elastic peak intensity is influenced more strongly by surface morphology (roughness and porosity) than by surface excitations and quasielastic scattering of electrons by hydrogen atoms. Copyright © 2007 John Wiley & Sons, Ltd.

The steady-state surface compositions of the polar (O and Zn terminated) faces of ZnO{0 0 0 1} produced by low energy (0.3–2 keV) Ar + ion bombardment were studied by Auger electron spectroscopy and electron energy loss spectroscopy. The alterations produced by the ion bombardment using different ion energies were monitored by calculating the intensity ratios of the low and high energy Zn Auger peaks (59 eV and 994 eV, respectively); Zn and O Auger peaks (59 eV and 510 eV, respectively). Based on the dependence of these ratios on the ion energy and termination of the surface, we could conclude that the stability of the Zn face is higher against the low energy argon ion bombardment-induced compositional changes than that of the O face.

The steady state surfaces of ion bombarded 3C-, 4H- and 6H-SiC samples were studied by means of reflected electron energy loss spectroscopy (REELS). The REELS exhibit a well-defined loss peak in the region of about 20 eV. The position of the maximum of the loss peak depends on the bombarding ion energy (decreasing with increasing ion energy), and on the primary electron beam energy (increasing with increasing primary energy). This behavior can be explained if we suppose that the plasmon energy in the altered layer (produced by ion bombardment) is different from that of the unaltered bulk. In this case the measured loss peak is the sum of two overlapping plasmon peaks. With modeling the system as a homogeneous altered layer and a homogeneous unaltered substrate the plasmon energy in the altered layer was derived to be 19.8 eV. The large change of the plasmon energy with respect to the bulk value of 23 eV is explained by a thin low density overlayer on the surface of the sample produced by the ion bombardment.

Electrons impinging into a solid surface produce excitations in the surface layer. The elastic reflection coefficient of a solid (i.e. elastic peak) is reduced by surface losses. Selected conducting polymers were studied with elastic peak electron spectroscopy (EPES) and reflection electron energy loss spectroscopy (REELS). The electron inelastic mean free path (IMFP) was determined using EPES with Ag and Si references and corrected for surface excitations, characterized by the surface excitation parameter Pse(E). A new procedure was developed for experimental determination of the parameter Pse(E), a further development of Tanuma's work. It is based on comparison of experimental and calculated integrated elastic peak ratios of sample and reference. Another procedure was based on the REELS method. Pse(E) of selected polymers were determined for E = 0.2–2.0 keV using a HSA analyser. Experiments were evaluated by Monte Carlo simulation using NIST elastic scattering databases. The IMFP values for polymers were calculated by Gries, Cumpson and TPP-2M formulae. Material parameter data, ach, using Chen's approach for selected polymers, and IMFPs of polyethylene corrected for surface excitation are presented. Copyright © 2004 John Wiley & Sons, Ltd.

Elastic peak electron spectroscopy (EPES) provides inelastic mean free path (IMFP) values in the near-surface region. Such values, which will be called effective IMFPs, might be different from these derived from bulk parameters. In this work we derive effective IMFP values from EPES measurements in the range of 300–2000 eV for SiO2 and Si3N4 using a Si reference. Corrections for surface excitation are applied. Our effective IMFP values agree well with those calculated from optical data in the case of SiO2; that is, the ion sputtering does not alter the SiO2 surface significantly. On the other hand, systematic deviations between our data and those provided by a predictive formula were found in the case of sputtered Si3N4. These differences are attributed to alteration in the surface layer caused by sputtering.

Ion sputtering induced surface composition changes by applying various ions (He + , Ne + , Ar + , Xe + ) in the energy range of 0.2–1.5 keV, was measured by AES on the polar faces of 6H–SiC{0 0 0 1}. Carbon enrichment was observed on both faces, and it was different if Ne + , Ar + , Xe + ion sputtering was applied with ion energy lower than 0.4–0.8 keV (depending on projectile); no different enrichment was found for He + ion bombardment at any energy (in this range). Thus C/Si ratio measured by AES after low energy ion (e.g. Xe + ) bombardment can be used to identify polarity of the surface.

The surface excitation produced by impinging or escaping electrons is a competitive process to elastic backscattering. It affects the intensity of Auger and XPS peaks and is characterized by the surface excitation parameter Pse. This appears in the surface loss peak I(Epls), and possibly a surface plasmon. In our work Pse is defined as the ratio of the probability to create a surface plasmon/elastic scattering and is deduced from the integrated surface loss peak and elastic peak, respectively. Our procedure is based on reflection electron energy loss spectroscopy and elastic peak electron spectroscopy spectra and Kλi spectra (K is the inelastic scattering cross-section and λi is the inelastic mean free path), determined using Tougaard's method. The normalized Kλi curves are fitted to the spectrum at E = 5 keV (primary energy) and EL = Epl1 (volume plasmon), approximated with the Lorentzian type three-parameter formula of Tougaard. For E>Epl1, the normalized curves are overlapping and Pse is deduced from the integrated difference spectra fitted with the Tougaard cross-sections. The procedure was applied on materials exhibiting surface and volume plasmons: III–V semiconductors (GaAs, InSb) and In and Sb metals. The REELS experiments were carried out with an ESA 31 HSA spectrometer covering the E = 0.2–5 keV energy range. Copyright © 2002 John Wiley & Sons, Ltd.

The inelastic mean free paths (IMFPs) of three AuPd alloys were determined by means of elastic peak electron spectroscopy (EPES) in a round-robin study in four laboratories using different types of electron spectrometers in the energy range 0.5–2 keV. The scatter of the IMFP values was in the range of 25%. Within this accuracy the inverse IMFP of these alloys can be calculated by the weighted sum of the inverse IMFPs of the alloying elements. Reflected electron energy loss spectra also were measured and the Kl curves, calculated by the method of Tougaard, were used for estimating the inelastic processes in the alloys. The source of the scatter in the IMFPs obtained in the present work is discussed. Copyright  2002 John Wiley & Sons, Ltd.

A new type of titanate nanotube (TNT) coating is investigated for exploitation in biosensor applications. The TNT layers were prepared from stable but additive-free sols without applying any binding compounds. The simple, fast spin-coating process was carried out at room temperature, and resulted in well-formed films around 10 nm thick. The films are highly transparent as expected from their nanostructure and may, therefore, be useful as coatings for surface-sensitive optical biosensors to enhance the specific surface area. In addition, these novel coatings could be applied to medical implant surfaces to control cellular adhesion. Their morphology and structure was characterized by spectroscopic ellipsometry (SE) and atomic force microscopy (AFM), and their chemical state by X-ray photoelectron spectroscopy (XPS). For quantitative surface adhesion studies, the films were prepared on optical waveguides. The coated waveguides were shown to still guide light; thus, their sensing capability remains. Protein adsorption and cell adhesion studies on the titanate nanotube films and on smooth control surfaces revealed that the nanostructured titanate enhanced the adsorption of albumin; furthermore, the coatings considerably enhanced the adhesion of living mammalian cells (human embryonic kidney and preosteoblast).

In the present work our experimental results on the energy shifts and energy widths (full width of half-maximum) of the quasi-elastic peaks (1-5 keV) obtained using a high-energy-resolution electron spectrometer and different (C, Si, Ni and Au) surfaces are compared with those calculated by assuming single elastic scattering on free atoms having a Maxwell-Boltzmann thermal velocity distribution. There is a good agreement in the case of the energy shifts as well as for the energy broadenings obtained using higher atomic number polycrystalline samples (Ni, Au). In the case of Si, however, the measured energy broadening is systematically larger by 15-20% than the calculated broadening for the whole primary beam energy range. Compared with the calculated values, considerably larger broadenings (by 30-60%, depending on the primary beam energy) were observed for carbonic samples. The contribution of the multiple elastic scattering to the yield of the electrons backscattered elastically, and the effect of the multiple scattering on the energy shifts and Doppler broadenings, have been determined using Monte Carlo simulations. Our results show that multiple scattering causes only small changes in energy shifts and energy broadenings of elastic peaks in the case of the samples and primary electron energy region studied.

Two, NiFe/Co based spin valve structures, prepared by magnetron sputtering were studied by means of high-resolution Auger depth profiling. Strong interfacial mixing was found in the case of ‘as deposited’ specimens. A 2 h heat treatment at 260°C resulted in demixing, that is the width of interfacial mixed zone became less than that in the ‘as deposited’ condition.

Quantitative surface, interface and thin film analysis is based in practice on reference standard samples. The elastic reflection coefficient r e of a surface is a material parameter that can be determined from the elastic peak intensity. Absolute values of r e have been published by several authors, mainly working with a retarding field analyser. Koch published the angular distribution r e ( Θ ) %/sr for a number of elements covering the E =400–2400 eV energy range. Goto developed a cylindrical mirror analyser for elastic current measurements and published results on graphite, Ni, Ag, Cu, Au and Si. The transmission of the ESA 31 (ATOMKI) and DESA 100 electron spectrometer of Staib were determined from the backscattering spectra of standard samples. Comparison of experimental r e ( E , Z , 138°) data of Koch with those of Goto exhibited nearly constant ratio close to 5 that slowly decreased with E . The transparency of Goto's CMA was found nearly 20%, near to his estimated value. The elastic current data can be affected by the spectrometer energy resolution integrating the loss spectrum adjacent to the elastic peak. Spectrometer correction for that is needed. The transmission (response) of the ESA 31 and DESA 100 was determined. The elastic peak can be used as internal reference standard for quantitative AES and electron energy loss spectroscopy.

Various Ge/Si layer structures (multilayers with 2 and 3 nm layer thicknesses, step function transition, and 1 nm Si imbedded between thick Ge layers) were depth profiled by using 1 keV He+ and Ar+ sputtering with angle of incidence of 83°. The specimen was rotated during sputtering. The depth resolution determined on the step function transition weakly depended on the type of projectile used. Similarly there was not a strong deviation of depth profiles recorded on the imbedded Si layer (thickness 1 nm) if Ar+ or He+ projectile was used. In contrast a serious difference between the depth profiles measured by Ar+ and He+ sputtering was observed in the case of the multilayer systems. Based on these observations we concluded that the depth resolution (determined according to the standard) is not a sufficient characterization of a depth profiling device. It is proposed that depth profiling of some standardized multilayer structure, with layer thicknesses of 1–2 nm should also be added to the characterization ...

The kinetics of aluminium-induced crystallisation of thin amorphous germanium layers have been studied by electrical conductivity measurements. Al/a-Ge bilayers (5/50 nm) were prepared by thermal evaporation onto NaCl substrate at constant temperature (220°C) in a high vacuum (10 −6 Torr), between two electrical contacts, previously prepared on the substrate. The changes in the electrical conductivity due to deposition and phase transformation of amorphous germanium to polycrystalline germanium were recorded as a function of time. Crystallisation starts from aluminium/amorphous germanium interface forming a polycrystalline germanium layer. Using a model of conductors connected in parallel for the system formed by amorphous germanium, polycrystalline germanium and aluminium layers, the time dependence of the crystallisation front motion was calculated. The experiment resulted in a parabolic dependence of the thickness of polycrystalline germanium layer on the annealing time, suggesting that crystallisation of amorphous germanium induced by aluminium is diffusion-controlled. Aluminium concentration profile in depth as measured by AES depth profiling supports further this conclusion.

The inelastic mean free path (IMFP) of electrons has been determined for selected elemental solids using elastic peak electron spectroscopy (EPES) and a Ni standard. The IMFP was evaluated for the range of 500–3000 eV on Cr, Mo, Ge and Si materials. The Ni standard surface has been prepared by electrolysis and HV vapour deposition. Its quality was verified by AES and STM. The theoretical model relating the elastic peak intensity to the value of the IMFP was based on relativistic scattering cross sections and the multiple elastic scattering events were simulated by a Monte Carlo procedure. Reasonable agreement of the obtained IMFP values and their dependence on the energy with the data by Tanuma et al. and by Ashley et al. was found.

Auger in‐depth profiles were measured on a Mo–Si multilayer structure, consisting of 45 periods of 3.3 nm molybdenum and 3.6 nm silicon layers, by means of Ar ion bombardment with rotated specimen and a glancing incidence ion beam probe. The relative sputtering yield of Si and Mo is determined in the ranges of 2–6 keV ion energy and 80°–87° incidence angle with respect to the surface normal. It is shown that the depth resolution depends strongly on the ion energy. The depth resolution changes immediately when the ion energy is changed. This observation is explained by the fact that the depth resolution in our experiment is limited by ion mixing and not by surface roughening. Attempts to determine the initial structure from the measured profile through application of Liau’s model on ion sputtering were not completely successful.

RF-sputtered CrSiO cermet films deposited without and with a bias (200 V) have been studied by XPS and AES. Samples as deposited, etched by HF solution as well as annealed at temperatures up to 600°C have been considered. XPS results showed that the surface of the as-received samples were depleted in Cr and enriched in O with respect to the target composition. Silicon and Cr were present in both oxidized and reduced forms in the surface layer. Ar+ ion sputter profiles revealed that the composition of the subsurface approached that of the target and that Cr was present in the subsurface in reduced and Si in both oxidized and reduced states. AES in-depth profiling resulted in element concentration trends similar to but element ratios different from those observed by XPS. This was attributed to preferential sputtering coupled with the significantly different sampling depths of the two techniques. Cr3Si was identified by x-ray diffraction in samples treated at 600°C, but not even traces of it could be detected by this method below 400°C. The Si Auger parameter determined by XPS proved to be more sensitive in identifying silicide-type bonds in the CrSiO layers studied.

The consistency and accuracy of inelastic electron mean free paths (IMFPs) determined from comparison of the intensity of elastically reflected electrons with theoretical calculations were studied. The variation with experimental geometry, spectrometer energy resolution and the procedure for background subtraction was studied. Four different types of spectrometers-double pass cylindrical mirror analyser (CMA) preretarded CMA, hemispherical analyser (HSA) and retarding field analyser (RFA) - with widely different geometries and energy resolutions, placed in four different laboratories in three countries, were used. Four background subtraction methods (Shirley, linear, Tougaard and ELPSEP) were applied to isolate the elastic peak intensity from the reflected electron spectra. It was found that the IMFPs determined with data from the double pass CMA deviated considerably more (by a factor of 2) from the average values as well as from theoretical IMFP values than IMFPs determined with data from the other spectrometers. The data from the double pass CMA were therefore excluded from the statistical analysis. The root mean square (RMS) deviation of the IMFP from a function fitted to the data was 1.6-2.8 A, depending on the background subtraction method, and it is smallest for the Tougaard method. The RMS deviation from IMFP values calculated by Tanuma et al. is 2.1-3.2 A, again with the smallest value for the Tougaard method. The percentage deviation of the results using a Tougaard background from Tanuma et al. values is 12.6%. The results point to the conclusion that the major contribution to the inaccuracies in IMFPs determined with this method is not the background subtraction procedure but rather the lack of accuracy of the presently available models for elastic electron scattering, i.e. atomic elastic scattering cross-sections and effects of crystallinity that are not included in the presently applied models.

In the case of conventional Auger in-depth profiling, the depth resolution increases with the thickness of the removed layer. It was demonstrated that by rotating the specimen, the depth resolution improves drastically in certain cases. Independently from this, A. Barna developed a phenomenological model to describe the change of surface topography developing due to ion sputtering. Based on his results, an Auger in-depth profiling device has been built.

FeNi alloys have been studied by electron spectroscopy varying the sampling depth of analysis with the primary energy of ILS and comparing it to AES. An on-line computer operated CMA analyzer was used at 2 and 3 keV primary energy. AES and ILS were based on LMM transitions and 2 p 3 2 shell electron excitation respectively of both Fe and Ni. Inelastic loss peaks were evaluated taking into account single elastic scattering. A simple formula is deduced containing Reimer's elastic cross sections. The electron IMFP needed for AES and ILS was determined by EPES. New IMFP values for FeNi alloys are presented. Quantitative analysis by ILS and AES provided reasonable agreement.

The surface composition of several MoNi alloys was studied by X-ray photoelectron spectroscopy (XPS). The surface of each sample was scraped in situ and extensively sputtered by 1 keV Ar + ions. It was assumed that the surface composition after scraping is identical to the bulk composition. The ratio of the Mo and Ni elemental sensitivity factors was estimated as a function of the alloy composition. The change of surface composition during bombardment with 1 keV Ar + was also determined. The steady state composition was established and the ratio of elemental sputtering yields as a function of alloy composition was estimated. It was shown that the assumption of constant sensitivity factors and sputtering yields may result in a pronounced error in the quantitative XPS analysis. The influence of annealing on the surface composition was investigated for 25 at% Mo by Auger electron spectroscopy (AES). It was found that the surface is enriched in Ni after annealing.

The elastic backscattering probability Pe of electrons is proportional to the product of the inelastic mean free path (IMFP), effective backscattering cross section (σeff), and atomic density (N). Thus, experimental evaluation of Pe, e.g. from the elastic peak intensity measurements, enables the determination of the IMFP. σeff can be calculated by integrating the differential elastic scattering cross sections using a simplified model based on the first Born approximation and the Thomas–Fermi–Dirac atomic potential. No significant difference in the values of σeff was found using the Thomas–Fermi, the Thomas–Fermi–Dirac and the Hartree–Fock atomic potentials or integrating the scattering cross sections tabulated by Fink et al. From the experimental values of Pe reported by Schmid et al. and by Gergely the IMFP was determined for a number of elements. A good agreement was found with the data on the IMFP published in the literature. Comparing the elastic peak of two samples and using the data of Ashley and Tung as reference values, the IMFP has been determined for GaP, GaSb, InP, InSb and Si3N4 samples. Good agreement with the data of Ashley and Tung was obtained for Si, Ge, SiO2 and GaAs.

A new method for determining the inelastic mean free path was applied to the ordered polycrystalline AlNi alloy. The results obtained agree well with the literature data.