Abstract: We present a study of the photoresist (PR) etching and the low-k materials damage using a
ferrite-core inductively coupled plasma (ICP) etcher, in order to develop an etching process for the
low-k dielectric devices. We reveal that the N2/O2 flow ratio and bias power affected the PR etching
rate. By Fourier transform infrared spectroscopy and HF dipping test, we investigated the effect of the
gas flow ratio and bias power on the amount of etching damage to the low-k material.
Abstract: Our recently proposed quantum approach to biomolecular isomeric-conformational
changes and recognition processes, additionally supported by biomolecular resonant recognition
model and by quantum-chemical theory of biomolecular non-radiative resonant transitions, is
hereby extended to cascade resonant transitions via close intermediate participating isomeric states -
which might be related to polaron/soliton-like energy and charge transport mechanisms in Q1Dmolecular
chains, whose relevance is explored in this paper.
Abstract: Carriers mobility model of olygomer and polymer semiconductor based OFET (Organic
Field Effect Transistor) structures is presented in this paper. Starting from the conduction
mechanism in the mentioned organic materials, a carrier mobility dependence on temperature,
electric field and trap density μ(T,E,NT) was investigated, inspiring directly the current-voltage I(V)
model of OFET structures. Subsequent simulations were also performed and the obtained results
compared with the data available in the literature.
Abstract: Several approaches for immobilization of arsenic (As) based on the transformation of its
soluble forms (compounds) into highly insoluble arsenate apatite Ca5(AsO4)3OH have been
proposed. These immobilization techniques are successfully applied in treatment of industrial waste
containing As. Quite the contrary, treatment of soil contaminated with As by apatite amendments,
instead of immobilization of this toxic element, increases its mobility and bioavailability. The
mechanism underlying these opposite effects still remains elusive. Here, the stability analysis of
different calcium arsenates: Ca5(AsO4)3OH, Ca4(AsO4)2(OH)2, Ca3(AsO4)2 Ca5H2(AsO4)2 and
CaHAsO4 was performed, which is based on the calculation of the ion-ion interaction potential
(IIIP). It has been demonstrated earlier that IIIP, representing the main term of the cohesive energy,
is a suitable parameter for assessment of mineral stability. According to the results of this analysis,
arsenate apatite with IIIP value of -0.578 Ry represents the most stable chemical form among
analyzed compounds. Based on this finding, we proposed a mechanism of formation of arsenate
apatite in the presence of hydroxyapatite. This mechanism can explain the suitability of this
approach for the treatment of industrial waste and its limitations for in situ treatment of soil and
water contaminated with As.
Abstract: The adequate choice of different target materials for X-ray generators is a very important
subject of engineers’ practice and research. In the present work we analyze theoretically the
transport of electrons through the anode material and the production of the corresponding
bremsstrahlung radiation. In our analysis we simulate the particle transport with the help of the
FOTELP code, which is based on the Monte Carlo simulation. Our main aim is to develop an
efficient and handy method, which could be helpful in improving the design of the X-ray tube
components and in reducing of the patient dose, while keeping the image quality. The obtained
results are encouraging.
Abstract: CdZnTe detectors have been employed in diagnostic X-ray spectroscopy. This paper
presents the Monte Carlo calculation of X-ray deposited energy in a CdZnTe detector for different
energies of photon beam. In incident photon direction, the distribution of absorbed dose as
deposited energy in detector is determined. Based on the dependence of the detector response on the
thickness and different Zn fractions, some conclusions about changes of the material characteristics
could be drawn. Results of numerical simulation suggest that the CdZnTe detector could be suitable
for X-ray low energy.
Abstract: The gamma-ray irradiation causes positive charge traps formation in silicon dioxide films
and at silicon dioxide - silicon interface of MOS devices, and the threshold voltage shift in MOS
transistors. Here, the Monte Carlo model was used to develop an approach for estimating gammaray
induced traps spatially distributed in silicon dioxide films. This is combined with the model of
energy distributed traps at silicon dioxide - silicon interface. The developed model enables gammaray
induced charge and threshold voltage shift determination as a function of gamma-ray doses. The
threshold voltage measurements at a single specified current, both of radiation sensitive and
radiation hardened MOS transistors irradiated with different doses of gamma-ray are compared with
the developed model and good agreement are obtained.
Abstract: Electron mobility for the silicon-based devices is one of the most important parameters,
which determine the behavior of components. Mobility depends on silicon purity, doping level,
presence of lattice defects and electric field in the particular device. These influences are
particularly important for the nano-scaled devices since it is much more difficult to control the
thickness of the active layer, uniformity of impurity doping and appearance of parasitic bipolar
devices and capacitances. We have investigated a relationship between the electron mobility for the
silicon based PD (Partially Depleted) SOI (Silicon On Insulator) NMOS (n-type Metal Oxide
Semiconductor) Devices and the related kink effect, which appears as a consequence of the charge
accumulation at the interface of the Buried Oxide. We relate PD SOI NMOS Device technology
parameters to the kink effect and we propose a guiding line for alleviating this effect.
Abstract: The calculations of the low-energy attachment cross section to metallic clusters are
investigated. Low energy electrons are taken as slow enough to excite a giant dipole collective
resonance within the cluster. The calculations are more refined than the earlier ones – they do not
depend on the experimental data, and we improved RPAE calculation of the collective resonance in
the cluster. The results are interesting for the nano-region and designing of new materials.
Abstract: Transformations of glasses from the multicomponent pseudobinary system
(As2Se3)100−x(SbSI)x were analyzed from the aspect of determining the glass transition temperature
Tg, activation energy of the process Et, and characteristic changes of the specific heat. The
established dependence of Tg on glass composition and heating rate served as the basis for
determining the activation energy of glass transition process Et. An abrupt increase in the specific
heat cp at the glass transition temperature was analyzed with the aim of classifying the materials
according to the criterion of the so-called 'fragility'. It was found that the investigated glasses, i.e.
their melts, belong to the group of thermodynamically 'strong' melts.