AES Profiling Research Articles

Tritium-permeation-barrier properties of erbium oxide (TPB) coating on CLAM steel

Erbium oxide (Er2O3) coatings are considered as the candidate for tritium permeation barrier (TPB) because of its low permeation reduced ratio. The enhanced adhesion between TPB layer and metal substrate is one of the key issues for the high reliability. In this work, erbium coatings were firstly prepared by radio frequency (RF) magnetron sputtering and then annealed to generate Er2O3 TPB coatings, accompanied with Er2Fe17 due to inter-diffusion between Er and steel substrates. The coatings are compact and smooth if the annealing temperature is above 873 K. The samples are insulator at room temperature, and meet the requirement of TPB in blanket. The adhesion of coatings could be improved with elevating annealing temperature. According to the AES profile, a thickness controllable TPB multi-layered model of Er2O3/Er2O3+Er/Er/Er2Fe17/Fe is proposed.

Preferential sputtering and mass conservation in AES and SIMS depth profiling

The preferential sputtering and the mass conservation upon AES and SIMS depth profiling have been evaluated quantitatively based on the Mixing-Roughness-Information (MRI) model. The simulation results demonstrated that (a) the preferential sputtering plays an important role in the reconstruction of the true concentration-depth profile; (b) the mass conservation is a nature consequence in SIMS depth profiling but it is not fulfilled in AES depth profiling; (c) the layer thickness can be determined by applying the mass conservation law in AES depth profiling if the atoms preferentially sputtered out from the mixing zone are taken into account.

224PD - Efficacy and safety of BCD-022, trastuzumab biosimilar candidate, compared to herceptin: Results of international multicenter randomized double blind study in patients with HER2+ mBC

BCD-022 demonstrated equivalence to Herceptin in a comprehensive comparability physicochemical, non-clinical PK and PD studies, as well as phase I PK clinical study in patients with HER2+ mBC. 126 patients with HER2-positive metastatic BC were randomly assigned into 2 groups at a ratio of 1:1 to receive BCD-022 or Herceptin at a loading dose of 8 mg/kg and then in maintenance dose of 6 mg/kg in combination with paclitaxel (175 mg/m2) every 3 weeks up to 6 cycles of therapy or until progression or unbearable toxicity. ORR (primary endpoint) in both groups had no statistically significant differences: 53.57% (95% CI 40.70 – 65.98%) in BCD-022 group and 53.70% (95% CI 40.60 – 66.31%) in Herceptin group. The lower limit of 95% CI for ORR difference between the groups (-19.83%) did not exceed the non-inferiority margin, hence BCD-022 is non-inferior to Herceptin. There were also no differences between the groups for all other efficacy parameters: CR (5.36 vs 3.70%), PR (48.21 vs 50.00%), SD (25.00 vs 25.93%) and progression rate (21.43 vs 20.37%) in BCD-022 and Herceptin group, respectively. AEs profiles of BCD-022 and Herceptin were equivalent. Rate of all observed AEs including severe AEs had no statistically significant difference between the groups. Most AEs were associated with chemotherapy: neutropenia (73.02 vs 73,77%), anemia (82.54 vs 77.05%), leukopenia (73.02 vs 68.85%), lymphopenia (69.84 vs. 65.57%), thrombocytopenia (17.46 vs 29.51%), hyperglycemia (57.14 vs 70.49%), ALP increase (38.68 vs 42.62%), AST increase (42.86 vs 42.62%), ALT increase (33.33 vs 40.98%), alopecia (33.33 vs 34.43%), arthralgia (17.46 vs 18.03%) etc. Cardiovascular events specific for trastuzumab included: tachycardia (34.92 vs 19.67%), arterial hypertension (20.63 vs 18.03%), atrial fibrillation (0 vs 3.28%), extrasystoles (0% vs 1.64%), CAD gr.1 (1.59 vs 0%) and aggravated myocardiodystrophy (1.59 vs 0%). Binding antibodies with neutralizing activity were detected only in 1 patient in each group that indicated to low immunogenic potential of both drugs. BCD-022 demonstrated non-inferiority to Herceptin in patients with HER2+ mBC.

Quantitative analyses of photovoltaic CIGS thin films via SIMS depth profiling with elemental ions and MCs+ clusters

Polycrystalline copper–indium–gallium–diselenide (CIGS) is used as an absorber in thin‐film solar cells because of its appropriate band gap and high absorption coefficient for solar radiation. Many research groups have determined the CIGS compositions related to solar cell efficiency. In this work, three different Cu(In,Ga)Se2 thin films were prepared on molybdenum back contacts deposited on soda‐lime glass substrates via a three‐stage evaporation or, alternatively, a two‐step selenized process. Surface analyses via AES, XPS, and SIMS were used to characterize the CIGS thin films and compare their depth profiles. The MCs+ clusters were detected to improve the quantification of major compositions in the CIGS thin films while suppressing the matrix effect in the SIMS depth profiles. The compositional distribution in the MCs+‐SIMS was in good agreement with the AES and XPS depth profiles. The MCs+‐SIMS results proved more quantitatively accurate than those from the elemental SIMS while comparing to ICP‐AES data. Copyright © 2014 John Wiley & Sons, Ltd.

Effects of Cu/In ratio of electrodeposited precursor on post-sulfurization process in fabricating quaternary CuIn(S,Se) 2 thin films

This paper reports the analysis of S diffusion into electrodeposited CuInSe 2 (CISe) precursors during post-sulfurization treatment at 500 °C in an Ar/H 2S ambient. The characterizations of the sulfurized films by X-ray diffraction, grazing-incidence X-ray diffraction, Auger electron spectroscopy and micro-Raman spectroscopy allow the observation of the strong dependence of S incorporation into these films on the Cu/In ratio of the precursor. AES profiles reveal higher S content along the depth of Cu-rich film than Cu-poor film after sulfurization. Raman Scattering shows that copper sulfoselenides Cu–(Se,S) are only detected in Cu-rich samples. The re-crystallization of films during sulfurization was analyzed and it is presumed that quasi-liquid Cu–Se phases, which are related to Cu/In ratio of precursor, promote continuous incorporation of S into these films.

Chemical-state information obtained by AES and XPS from thin oxide layers on duplex stainless steel surfaces

Thin oxide films were produced by the exposure of polished, sputter-cleaned metallic surfaces kept in UHV to several thousands of Langmuirs at 10 −5 mbar oxygen yielding oxide layers of several nanometers. Metallic substrates used were iron, chromium and duplex stainless steel (DSS 2205). AES and XPS profiling analyses were performed. An attempt was made to use certain features observed in the AES spectra, i.e. to correlate Fe and Cr MNN peak shapes with the chemical state of the corresponding element. A similar approach has been tried before and may, when combined with high-lateral-resolution AES, provide small-area chemical-state information. Localized chemical-state information derived from the MNN peak shapes by a Linear Least Squares Fit (LLSF) procedure appeared to match reasonably well with that provided by XPS, which is averaged over approximately 2 mm 2. This is a plausible result for a thin homogeneous layer on a polished substrate.

Depth profile analysis of nanometric multilayer coatings by radio-frequency glow discharge optical emission spectroscopy

Radiofrequency glow discharge optical emission spectrometry(RF-GD-OES) was used to quantitatively analyze the depth of nanometric Cr/Ni multilayers on a silicon substrate. The technique permitted rapid and accurate depth profiling of multilayers, down to the nanometer range. The analytical parameters were optimized for the RF-GDOES depth quantitative analysis of Cr/Ni multilayers on a Si substrate. To validate the RF-GD-OES results, a TEM image was obtained in addition to performing the AES and SIMS depth profiling. The findings indicate that RF-GDOES is a promising analytical tool for the accurate and rapid depth profiling of nanometric metal multilayers on semiconducting substrates.

A randomized pilot study comparing safety and efficacy of irinotecan plus S-1 (IRIS) plus bevacizumab (BV) and modified (m) FOLFIRI plus BV in patients (pts) with metastatic colorectal cancer (mCRC): First report of T-CORE0702.

496 Background: Sequential combination with irinotecan (CPT-11) and S-1 (IRIS) is active and safe regimen against mCRC (ASCO2008, abstract #4107, T. Yoshioka et al. Br J Cancer 101: 1972-77, 2009). The aim of this prospective randomized pilot study was to compare safety (CTCAE v3.0, primary endpoint) and efficacy (RR and PFS, secondary endpoint) of IRIS with mFOLFIRI when these were used with BV. Methods: Sixty pts with mCRC were randomized to compare 30 pts for IRIS+BV (CPT-11 150 mg/m2 infusion on day 1, S-1 80 mg/m2 orally on day 3-16, q3w) with 30 pts for mFOLFIRI+BV (CPT-11 150mg/m2). 57 pts (IRIS arm 29, mFOLFIRI arm 28) were evaluable. Most of them were treated as first-line therapy. Results: Background of pts was well balanced among two arms. Although G3/4 hematological AEs profiles were similar between two arms, G2-4 neutropenia was significantly lower in IRIS arm than mFOLFIRI arm (56.6%, vs. 88.9%, p=0.01, χ2test). Among G3/4 nonhematological AEs, gastrointestinal toxicities were lower in IRIS arm than mFOLFIRI arm (anorexia: 3.5% vs. 17.9%, nausea: 0% vs. 7.1%, diarrhea: 6.9% vs. 14.3%, stomatitis: 0% vs. 3.6%). By χ2 test, nausea, vomiting and hair loss were significantly lower in IRIS arm than mFOLFIRI arm (p<0.05). GI-perforation, a BV-related severe AE, occurred in 2 pts only from mFOLFIRI arm and one of them was died as TRD. RRs (institutional evaluation) were 58.6% in IRIS (CR 2, PR 15, SD 11, and PD 1) and 55.1% in mFOLFIRI arm (CR 0, PR 16, SD 10, PD 2, and not evaluable 1). Our independent review committee will clarified definite RR and median PFS near future. Conclusions: Our IRIS+BV regimen is well tolerated, effective and appears to be a promising choice for pts with mCRC. [Table: see text]

Early stages of oxidation of uncoated and PVD SiO 2 coated FeCrAl foils

The high temperature oxidation characteristics of uncoated and SiO 2 PVD-coated FeCrAl foils have been investigated when exposed to laboratory air at 1000 °C during 1, 2, 4, 8, 16, 32 and 60 min. The oxidized samples were characterized using SEM, EDS, AES and SIMS. The results show that the presence of a 100 nm thin SiO 2 PVD coating significantly reduces the oxidation rate of the FeCrAl foil during early stages of oxidation. The decreased oxidation rate displayed by the SiO 2 coated FeCrAl foil is the result of the SiO 2 coating acting as an initial diffusion barrier promoting the formation of a predominantly inward growing Al 2O 3 layer during oxidation. Additionally, by using EDS analysis together with AES and SIMS depth profiling it was shown that the total concentration of Si in the grown oxide scale decreased during oxidation.

Structural and physical analysis on MOCVD Ti–Si–N films

Thin TiSiN flat films deposited by MOCVD have been analysed in order to evaluate their microstructure and physical properties. TEM, XRR and RBS techniques have been utilised as complementary analyses to evaluate thickness, density and composition. The main composition is Ti : N : Si = 0.9 : 1.1 : 0.14 with carbon and oxygen up to 5% as a result of organic residuals and oxidation. The analysis shows a layered structure which well correlates with deposition steps. TiN nanocrystals embedded in a SiN x -rich amorphous matrix result confined into each TiSiN deposited layer. The silane soak produces a low concentration silicon inclusion, mainly stabilising the grain boundaries and not affecting the TiN crystalline morphology. AES profiles show that the TiSiN film consists of Ti–N rich layers, separated by C and Si rich “interface” layers which are the result of the process sequence. Densification and crystallisation of the film were observed after high temperature annealing in vacuum, resulting in an electrical resistivity decrease. PECVD deposition of an oxide layer on TiSiN causes a strong oxidation and resistivity increase of the film.

Corrosivity of KCl(g) at Temperatures above Its Dew Point - Initial Stages of the High Temperature Corrosion of Alloy Sanicro 28 at 600°C

The influence of gaseous KCl on the high temperature oxidation of alloy Sanicro 28 (27Cr31Ni) at 600°C in 5% O2 (N2 in balance) is reported. The samples were exposed isothermally in flowing gas, the dew point of KCl being 590°C corresponding to a partial pressure of KCl of about 2·10-6 atm. The exposure time was 24, 72 and 168 hours. The samples were investigated by gravimetry, grazing incidence XRD, SEM/EDX and AES. The results show that the oxidation of Sanicro 28 at 600°C is accelerated by KCl(g) at metal temperatures above the dew point of the salt. KCl(g) reacts with the protective chromium rich oxide ((Fe1-xCrx)2O3) forming K2CrO4. The resulting chromium depletion of the oxide gives an increasing oxidation rate but does not trigger “breakaway” corrosion. The distribution of potassium chromate on the sample surface is strongly flow-dependent, showing that the rate of formation of potassium chromate is limited by the rate of transport of KCl(g) to the surface. No evidence for chlorine was found on the corroded samples by AES profiling or EDX.

Processing of chromium tungsten nitride hard coatings for glass molding

CrWN coatings were obtained on WC substrates by ion beam assisted deposition (IBAD). The surface roughness and crystallite size of the CrWN coatings were analyzed by atomic force microscopy and X-ray diffraction, respectively. With 4 at.% W doping, more than 50% decrease in crystallite size was found, and smaller surface roughness of about 2 nm was obtained due to the reduced crystallinity. This provided satisfactory surface condition requirements of 10 nm with practical optical accuracy for glass molding die. In addition, coatings were heated at 750 °C in air atmosphere for oxidation test. Formation of Cr 2O 3 would induce the surface roughness larger than 40 nm for both CrN and CrWN coatings. According to AES profile, coating CrWN1, with 4.4 at.% W, revealed similar penetration depth of oxygen in comparison to CrN, which was noted for excellent oxidation resistance. Therefore, comparable anti-oxidation behavior was expected for the CrWN coatings with low tungsten contents. It was demonstrated that CrWN coatings with 4.4 to 16.7 at.% tungsten alloying, exhibiting smooth surface roughness and improved hardness, could be considered to possess optimum composition for practical use.

Oxidation kinetics of the quasicrystalline i-AlCuFe phase compared with that of crystalline ω-AlCuFe and pure aluminum

The oxidation of the quasicrystalline alloy i-AlCuFe has been compared with that of tetragonal ω-AlCuFe and that of pure aluminum. At 600 °C, for low exposure to oxygen in UHV conditions (up to 5000 L), much smaller thicknesses of oxide have been observed on i-AlCuFe by AES and depth profiling. After oxidations of 10 5 L, oxide crystallites are clearly observed by SEM on the surface of ω-AlCuFe and pure aluminum, in particular in the center of the grains. Such is not the case on i-AlCuFe grains. These oxide crystallites give rise after ion etching to cones structure on the surface of ω-AlCuFe and pure aluminum whereas the i-AlCuFe surface remains very smooth. However when oxidation is performed at 700 °C, oxide crystallites also appear on the whole icosahedral grains. These results show that the crystalline and the quasicrystalline phases have a different kinetics in the oxide growth, due to, in particular, a delay in the nucleation and growth rate of the oxide on the quasicrystalline phase. It is assumed that this difference is linked to the impossible epitaxial growth of the γ-Al 2O 3 oxide on the aperiodic lattice of the i-AlCuFe phase.

SiBCN synthesis by high-dose N++C++BF2+ ion implantation

High-dose implantation processes of N++C++BF2+ have been performed on Si(100) substrates at 600 °C. Additional simple (N+,C+) and double (N++C+ and N++BF2+) implantations have also been produced to sequentially study the synthesis of different semiconductor compounds. FTIR spectra of all the samples before and after thermal annealing at 1200 °C have been acquired. When N+ and C+ are co-implanted the formation of a ternary phase of SiCN nature is suggested, meanwhile in the case of N+ and BF2+ competition between BN and Si3N4 takes place. The sequential implantation of the three species produces a stable surface region as deduced from the AES profiles. IR and XPS measurements suggest the formation of a SiCBxNy mainly formed by SiC with a significant content of B and N (∼20%).

Reducing the effective barrier height of a PtSi Schottky diode by a p+ doping spike using pulsed laser doping

The structure of PtSi/p+/p-Si fabricated by chemical vapour doping has been investigated for reduction of the Schottky barrier height. The interface structure and photoelectric properties of PtSi/p+/p-Si thin film structure have been studied. The results from AES profile analysis show that doped boron moves with the PtSi/Si interface during silicide growth. Concomitantly, the boron at the PtSi/Si interface out-diffuses to the Pt–PtSi interface. Finally, the boron piles up at the surface. It has been considered that the redistribution of the dopant boron is due to the solubility of the dopant in the silicide. The Schottky barrier height of PtSi/p+/p-Si is 0.13 eV (for cutoff wavelength 9.5 µm). That is lower than the 0.19 eV value of PtSi/p-Si (for cutoff wavelength 6.5 µm). Since the Schottky barrier height is lowered, the cutoff wavelength can be extended. Due to the Fowler dependence, the detector's quantum efficiency can be improved.

Study of the tribological modifications induced by nitrogen implantation on Cr, Mo and W

This article reports the study of the changes in the surface properties of metals of group VIa after their implantation with atomic nitrogen. Doses of 1E17 N +, 5E17 N + and 1E18 N + ions/cm 2 were implanted on polished samples of chromium, molybdenum and tungsten, in order to investigate the tribological effects due to implantation. This work is the continuation of the study carried out on groups IVb and Va, where the effects of nitrogen implantation were also evaluated. Microindentation hardness at low loads, friction and wear tests have been carried out on the different materials and doses in an attempt to relate surface modifications with the implanted dose. Microindentation hardness tests at low loads showed increases of at least a factor 2 in all the cases. Friction tests against Co–WC were performed, finding the higher friction reductions for molybdenum. AES and GDS profiles have also been performed to determine the nitrogen distribution after the implantation experiments.

Characterization of oxide layers on amorphous Mg-based alloys by Auger electron spectroscopy with sputter depth profiling.

Amorphous ribbons of Mg-Y-TM-[Ag] (TM: Cu, Ni), prepared by melt spinning, were subjected to electrochemical investigations. Oxide layers formed anodically under potentiostatic control in different electrolytes were investigated by AES and sputter depth profiling. Problems and specific features of characterization of the composition of oxide layers and amorphous ternary or quaternary Mg-based alloys have been investigated. In the alloys the Mg(KL(23)L(23)) peak exhibits a different shape compared to that in the pure element. Analysis of the peak of elastically scattered electrons proved the absence of plasmon loss features, characteristic of pure Mg, in the alloy. A different loss feature emerges in Mg(KL(23)L(23)) and Cu(L(23)VV). The system Mg-Y-TM-[Ag] suffers preferential sputtering. Depletion of Mg and enrichment of TM and Y are found. This is attributed mainly to the preferential sputtering of Mg. Thickness and composition of the formed oxide layer depend on the electrochemical treatment. After removing the oxide by sputtering the concentration of the underlying alloy was found to be affected by the treatment.

AES and SIMS investigation of diffusion barriers for copper metallization in power-SAW devices.

Barrier layers for Cu-metallization in surface acoustic wave (SAW) devices were investigated by AES and SIMS depth profiles. Two layered systems on LiNbO(3) substrate have been analyzed after annealing in air up to 400 degrees C. The investigated systems were (A) Ta(20 nm)/Cu(150 nm)/Ti(30 nm), deposited by electron beam evaporation, and (B) Ta(30)Si(18)N(52)(50 nm)/Cu(150 nm)/Ta(30)Si(18)N(52)(50 nm) deposited by magnetron sputtering. In system A the Ta layer shows oxidation in air for T>or=300 degrees C. Ti from the buffer layer diffuses into the Cu at about 100 degrees C, and segregates at the Ta/Cu interface for T>or=200 degrees C. Oxidation of the Ti layer starts at 300 degrees C. But no remarkable amounts of oxygen could be found in the Cu film. The depth profiles show that the TaSiN layer in system B operates as a more effective barrier for the Cu-SAW technology up to more than 300 degrees C.

Study of the tribological modifications induced by nitrogen implantation on metals of the Va group

This paper reports a comparative study of the modifications induced by Nitrogen implantation on metals of the Va group. Doses of 1.25×10 17, and 7×10 17 of atomic (N +) and of 3.5×10 17, and 6×10 17 molecular (N 2 +) Nitrogen at 150 keV energy were implanted on vanadium, niobium and tantalum polished samples, to investigate the tribological effects due to their reactivity with nitrogen. Microhardness at low loads (2 mN), friction and wear tests have been carried out on the different materials and doses in an attempt to relate the superficial modifications with the implanted dose. In addition, XPS analysis and AES profiles have been performed to investigate the nitrogen distribution and binding state after the different implantation experiments, in order to describe the relationship between the implanted dose, the surface mechanical modifications and the spectroscopic results.

Nitrogen ion implantation on group IVb metals:: chemical, mechanical and tribological study

This paper reports the study of the effects induced by nitrogen implantation on metals of the IVb group. Different doses of atomic and molecular nitrogen have been implanted on titanium, zirconium and hafnium samples to investigate their reactivity towards nitrides precipitation. Microhardness, friction and wear tests have been carried out. An increase in microhardness was found where, in some cases, was greater than 80%. Moreover, they were observed improvements in the wear resistance and a decrease in the friction coefficient. XPS analysis and AES profiles have been performed on all the implanted samples. The N1s XPS spectra show a binding energy corresponding to the nitride formation which is thought as the main cause of the mechanical and tribological improvement.