Copper trace analysis using Transient Ion Drift (TID) combined with a Rapid Thermal Annealing (RT... more Copper trace analysis using Transient Ion Drift (TID) combined with a Rapid Thermal Annealing (RTA) process is investigated. A double pulse method is implemented to allow unambiguous identification of the copper-induced capacitance signal. Use of a mercury probe as sensing Schottky barrier enhances the flexibility of the method and allows mapping of the contaminant. The method is evaluated on quantitatively contaminated silicon wafers and compared to Total X-ray fluorescence (TXRF).It is shown that in Czochralski grown material, the RTA is sufficient to dissolve most copper atoms into interstitial sites independently of their initial configuration. As a result, both, the surface and bulk contamination can be monitored by RTA/TID with a bulk detection limit close to 1011cm-3.In Float Zone material mapping of the quenched interstitial copper revealed the existence of defect reactions involving presumably vacancy clusters.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996
ABSTRACT Cross-sectional Transmission Electron Microscopy (XTEM) and infrared (IR) absorption hav... more ABSTRACT Cross-sectional Transmission Electron Microscopy (XTEM) and infrared (IR) absorption have been used to study the morphology of silicon carbide (β-SiC) layers synthesized by 50 keV carbon implantation in silicon as a function of implantation temperature and dose. Particular attention was devoted to relate the IR parameters (strength of the 794 cm−1 absorption line, damping factor) to the XTEM observations. The evolution with dose is particularly discussed on two samples implanted at 700°C, respectively at 1018 and 2 × 1018 cm−2. The effect of post implantation annealing at 1200°C is also investigated on samples implanted at 600 and 900°C. The major feature of this study is the demonstration that silicon can accommodate a limited amount of implanted carbon to form a β-SiC phase.
The electronic properties of organic semiconductors depend strongly on the nature of the molecule... more The electronic properties of organic semiconductors depend strongly on the nature of the molecules, their conjugation and conformation, their mutual distance and the orientation between adjacent molecules. Variations of intramolecular distances and conformation disturb the conjugation and perturb the delocalization of charges. As a result, the mobility considerably decreases compared to that of a covalently well-organized crystal. Here, we present electrical characterization of large single crystals made of the regioregular octamer of 3-hexyl-thiophene (3HT)8 using a conductive-atomic force microscope (C-AFM) in air. We find a large anisotropy in the conduction with charge mobility values depending on the crystallographic orientation of the single crystal. The smaller conduction is in the direction of π-π stacking (along the long axis of the single crystal) with a mobility value in the order of 10(-3) cm(2) V(-1) s(-1), and the larger one is along the molecular axis (in the direction normal to the single crystal surface) with a mobility value in the order of 0.5 cm(2) V(-1) s(-1). The measured current-voltage (I-V) curves showed that along the molecular axis, the current followed an exponential dependence corresponding to an injection mode. In the π-π stacking direction, the current exhibits a space charge limited current (SCLC) behavior, which allows us to estimate the charge carrier mobility.
Abstract The diffusion barrier behaviour of 20 to 200 nm thin Ta(N,O) films in the Cu/Si contact ... more Abstract The diffusion barrier behaviour of 20 to 200 nm thin Ta(N,O) films in the Cu/Si contact system was evaluated by materials and transient ion drift analysis. Using high resolution transmission electron microscopy, grazing incidence X-ray diffractometry, Auger electron spectroscopy and secondary ion mass spectrometry depth profiling it was revealed that the as-deposited amorphous-like Ta(N,O) diffusion barriers tend to partially recrystallize after annealing at 1 h/500°C without any detectable diffusion and/or reaction of Cu and Si up to at least 1 h/600°C. By making use of the newly developed transient ion drift technique for trace element analysis down to 5 × 10 11 cm −3 of interstitially dissolved Cu in Si, an exponential decrease of the Cu concentration on the Ta(N,O) barrier thickness is observed.
... Res., 8 (1993) 535. [16] M. Born and K. Huang, in DH Wilkinson and W. Marshall (eds.), Dynami... more ... Res., 8 (1993) 535. [16] M. Born and K. Huang, in DH Wilkinson and W. Marshall (eds.), Dynamical Theory of Crystal Lattices, International Series of Monographs on Physics, Oxford University Press, Oxford, 1954. [17] E Durupt, Thesis, Lyon, 1983. [18] BW Berreman, Phys. ...
ABSTRACT A scanning minority‐carrier transient spectroscopy with optical injection and full trans... more ABSTRACT A scanning minority‐carrier transient spectroscopy with optical injection and full transient analysis is developed. The continuity equation is solved with adequate injection and boundary conditions in order to determine the optimum experimental conditions and the corresponding optimum spatial resolution. A numerical treatment is implemented which filters out the noise component of the transient, improving the sensitivity of the technique. It allows us to make a fit to the transient, to check its exponential character and to treat certain cases of nonexponential behavior. The technique is applied first to a step distribution of laser‐induced defects and results can be obtained which are in good agreement with theoretical predictions. Finally, the gettering of gold to dislocations during a rapid thermal annealing is illustrated using this technique.
ABSTRACT The kinetics of interstitial iron precipitation in p‐type silicon are investigated. Duri... more ABSTRACT The kinetics of interstitial iron precipitation in p‐type silicon are investigated. During annealing, the iron charge state is controlled by the applied reverse voltage and its effect on the precipitation is studied. We observe that iron in the neutral charge state (Fe0 i ) precipitates preferentially in three‐dimensional nucleation centers while Fe+ i vanishes in the dislocation lines (rod‐like nucleation centers). These centers are created during the fast cooling procedure necessary to dissolve iron in the silicon matrix.
ABSTRACT We use the transient ion drift in a depletion region of a Schottky barrier to determine ... more ABSTRACT We use the transient ion drift in a depletion region of a Schottky barrier to determine ion diffusivities at moderate temperatures. The pulsed reverse bias leads to temperature dependent capacitance transients similar to deep level carrier emission transients. A simple theoretical model together with classical transient signal analysis provide the means to extract the ion diffusion constant. When applied to copper in silicon, diffusion data are obtained in a not yet investigated temperature range (280–400 K) which agree well with both low and high temperature diffusion data.
We report the influence of positional isomerism on the electronic, photophysical, physical and ch... more We report the influence of positional isomerism on the electronic, photophysical, physical and charge transport properties of dispiroacridine-indacenobisthiophene positional isomers.
Copper trace analysis using Transient Ion Drift (TID) combined with a Rapid Thermal Annealing (RT... more Copper trace analysis using Transient Ion Drift (TID) combined with a Rapid Thermal Annealing (RTA) process is investigated. A double pulse method is implemented to allow unambiguous identification of the copper-induced capacitance signal. Use of a mercury probe as sensing Schottky barrier enhances the flexibility of the method and allows mapping of the contaminant. The method is evaluated on quantitatively contaminated silicon wafers and compared to Total X-ray fluorescence (TXRF).It is shown that in Czochralski grown material, the RTA is sufficient to dissolve most copper atoms into interstitial sites independently of their initial configuration. As a result, both, the surface and bulk contamination can be monitored by RTA/TID with a bulk detection limit close to 1011cm-3.In Float Zone material mapping of the quenched interstitial copper revealed the existence of defect reactions involving presumably vacancy clusters.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1996
ABSTRACT Cross-sectional Transmission Electron Microscopy (XTEM) and infrared (IR) absorption hav... more ABSTRACT Cross-sectional Transmission Electron Microscopy (XTEM) and infrared (IR) absorption have been used to study the morphology of silicon carbide (β-SiC) layers synthesized by 50 keV carbon implantation in silicon as a function of implantation temperature and dose. Particular attention was devoted to relate the IR parameters (strength of the 794 cm−1 absorption line, damping factor) to the XTEM observations. The evolution with dose is particularly discussed on two samples implanted at 700°C, respectively at 1018 and 2 × 1018 cm−2. The effect of post implantation annealing at 1200°C is also investigated on samples implanted at 600 and 900°C. The major feature of this study is the demonstration that silicon can accommodate a limited amount of implanted carbon to form a β-SiC phase.
The electronic properties of organic semiconductors depend strongly on the nature of the molecule... more The electronic properties of organic semiconductors depend strongly on the nature of the molecules, their conjugation and conformation, their mutual distance and the orientation between adjacent molecules. Variations of intramolecular distances and conformation disturb the conjugation and perturb the delocalization of charges. As a result, the mobility considerably decreases compared to that of a covalently well-organized crystal. Here, we present electrical characterization of large single crystals made of the regioregular octamer of 3-hexyl-thiophene (3HT)8 using a conductive-atomic force microscope (C-AFM) in air. We find a large anisotropy in the conduction with charge mobility values depending on the crystallographic orientation of the single crystal. The smaller conduction is in the direction of π-π stacking (along the long axis of the single crystal) with a mobility value in the order of 10(-3) cm(2) V(-1) s(-1), and the larger one is along the molecular axis (in the direction normal to the single crystal surface) with a mobility value in the order of 0.5 cm(2) V(-1) s(-1). The measured current-voltage (I-V) curves showed that along the molecular axis, the current followed an exponential dependence corresponding to an injection mode. In the π-π stacking direction, the current exhibits a space charge limited current (SCLC) behavior, which allows us to estimate the charge carrier mobility.
Abstract The diffusion barrier behaviour of 20 to 200 nm thin Ta(N,O) films in the Cu/Si contact ... more Abstract The diffusion barrier behaviour of 20 to 200 nm thin Ta(N,O) films in the Cu/Si contact system was evaluated by materials and transient ion drift analysis. Using high resolution transmission electron microscopy, grazing incidence X-ray diffractometry, Auger electron spectroscopy and secondary ion mass spectrometry depth profiling it was revealed that the as-deposited amorphous-like Ta(N,O) diffusion barriers tend to partially recrystallize after annealing at 1 h/500°C without any detectable diffusion and/or reaction of Cu and Si up to at least 1 h/600°C. By making use of the newly developed transient ion drift technique for trace element analysis down to 5 × 10 11 cm −3 of interstitially dissolved Cu in Si, an exponential decrease of the Cu concentration on the Ta(N,O) barrier thickness is observed.
... Res., 8 (1993) 535. [16] M. Born and K. Huang, in DH Wilkinson and W. Marshall (eds.), Dynami... more ... Res., 8 (1993) 535. [16] M. Born and K. Huang, in DH Wilkinson and W. Marshall (eds.), Dynamical Theory of Crystal Lattices, International Series of Monographs on Physics, Oxford University Press, Oxford, 1954. [17] E Durupt, Thesis, Lyon, 1983. [18] BW Berreman, Phys. ...
ABSTRACT A scanning minority‐carrier transient spectroscopy with optical injection and full trans... more ABSTRACT A scanning minority‐carrier transient spectroscopy with optical injection and full transient analysis is developed. The continuity equation is solved with adequate injection and boundary conditions in order to determine the optimum experimental conditions and the corresponding optimum spatial resolution. A numerical treatment is implemented which filters out the noise component of the transient, improving the sensitivity of the technique. It allows us to make a fit to the transient, to check its exponential character and to treat certain cases of nonexponential behavior. The technique is applied first to a step distribution of laser‐induced defects and results can be obtained which are in good agreement with theoretical predictions. Finally, the gettering of gold to dislocations during a rapid thermal annealing is illustrated using this technique.
ABSTRACT The kinetics of interstitial iron precipitation in p‐type silicon are investigated. Duri... more ABSTRACT The kinetics of interstitial iron precipitation in p‐type silicon are investigated. During annealing, the iron charge state is controlled by the applied reverse voltage and its effect on the precipitation is studied. We observe that iron in the neutral charge state (Fe0 i ) precipitates preferentially in three‐dimensional nucleation centers while Fe+ i vanishes in the dislocation lines (rod‐like nucleation centers). These centers are created during the fast cooling procedure necessary to dissolve iron in the silicon matrix.
ABSTRACT We use the transient ion drift in a depletion region of a Schottky barrier to determine ... more ABSTRACT We use the transient ion drift in a depletion region of a Schottky barrier to determine ion diffusivities at moderate temperatures. The pulsed reverse bias leads to temperature dependent capacitance transients similar to deep level carrier emission transients. A simple theoretical model together with classical transient signal analysis provide the means to extract the ion diffusion constant. When applied to copper in silicon, diffusion data are obtained in a not yet investigated temperature range (280–400 K) which agree well with both low and high temperature diffusion data.
We report the influence of positional isomerism on the electronic, photophysical, physical and ch... more We report the influence of positional isomerism on the electronic, photophysical, physical and charge transport properties of dispiroacridine-indacenobisthiophene positional isomers.
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