Solid State Phenomena
Vol. 139
Vol. 139
Solid State Phenomena
Vol. 138
Vol. 138
Solid State Phenomena
Vol. 137
Vol. 137
Solid State Phenomena
Vol. 136
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Solid State Phenomena
Vol. 135
Vol. 135
Solid State Phenomena
Vol. 134
Vol. 134
Solid State Phenomena
Vols. 131-133
Vols. 131-133
Solid State Phenomena
Vol. 130
Vol. 130
Solid State Phenomena
Vol. 129
Vol. 129
Solid State Phenomena
Vol. 128
Vol. 128
Solid State Phenomena
Vol. 127
Vol. 127
Solid State Phenomena
Vols. 124-126
Vols. 124-126
Solid State Phenomena
Vols. 121-123
Vols. 121-123
Solid State Phenomena Vols. 131-133
Paper Title Page
Abstract: The silicon substrates were hydrogenated at approximately room temperature and
hydrogen concentration profiles vs. depth have been measured by SIMS. Czochralski grown (CZ)
wafers, both n- and p-type conductivity, were used in the experiments under consideration. For
analysis of hydrogen transport processes and quasichemical reactions the model of hydrogen atoms
diffusion and quasichemical reactions is proposed and the set of equations is obtained. The
developed model takes into account the formation of bound hydrogen in the near surface region,
hydrogen transport as a result of diffusion of hydrogen molecules 2 H , diffusion of metastable
complexes *
2 H and diffusion of nonequilibrium hydrogen atoms. Interaction of 2 H with oxygen
atoms and formation of immobile complexes “oxygen atom - hydrogen molecule” (O - H2 ) is also
taken into account to explain the hydrogen concentration profiles in the substrates of n-type
conductivity. The computer simulation based on the proposed equations has shown a good
agreement of the calculated hydrogen profiles with the experimental data and has allowed receiving
a value of the hydrogen molecules diffusivity at room temperature.
425
Abstract: In order to identify an appropriate low-temperature surface passivation that could be used
for bulk lifetime estimation of high resistivity (HR) (> 1 k·cm) silicon for radiation detectors,
different passivating layers were evaluated on n-type and p-type standard Czochralski (CZ), HR
magnetic CZ and HR float zone (FZ) substrates. Minority carrier lifetime measurements were
performed by means of a μW-PCD set-up. The results show that SiNx PECVD layers deposited at
low temperatures (≤ 250°C) may be used to evaluate the impact of different processing steps and
treatments on the substrate characteristics for radiation detectors. First results are obtained about a
preliminary thermal treatment experiment to evaluate the thermal stability of the passivating layers,
as well as the potential impact of the generation of thermal donors on minority carrier lifetime.
431
Abstract: Strains around a constricted matrix dislocation in a coherent twin grain boundary in
germanium is measured by a combination of high-resolution electron microscopy and geometric
phase analysis. Whilst strains in the grains on either side of the twin boundary agree closely with the
isolated dislocation case, significant additional strains are localized at the boundary plane. By
comparing the stresses and strains across the boundary plane, values for the elastic modulus of the
twin boundary are determined. They are found to exhibit a drastic decrease as compared to the bulk
and this is interpreted in terms of the non-equilibrium configuration of the boundary.
437
Abstract: Scanning probe microscopy with conductive tips has been used to image the dielectric
properties of ceramics with giant permittivity. In particular, measurements in impedance mode and
of local resistivity allowed to image the permittivity map on polycrystalline materials. Such imaging
allows to correlate the dielectric properties with the local sample structure and with defects inside
the single grains of the polycrystalline ceramics. However, artifacts due to surface imperfections
should be distinguished from bulk properties and eliminated.
443
Abstract: We have succeeded in imaging the leakage sites of hafnium silicate gate dielectrics of
metal-oxide-semiconductor field-effect transistors (MOSFETs) by using electron-beam-induced
current (EBIC) method. Leakage sites of p-channel MOSFETs were identified as bright spots under
appropriate reverse bias condition when the electron beam energy is high enough to generate
carriers in the silicon substrate. Most of the leakage sites were observed in the peripheries of
shallow trench isolation. These results suggest that some process induced defects are the cause of
leakage in these MOSFETs. Our observation demonstrates the advantage of EBIC characterization
for failure analysis of high-k MOSFETs.
449
Abstract: The low-temperature ultrasonic experiments are performed to measure the distribution of vacancy
concentration in the ingot of the Czochralski (CZ) silicon crystal grown with the pulling rate
gradually lowered. The elastic softening similar to that we recently found for the
floating-zone-grown silicon crystals is observed for the so-called vacancy-rich region of the ingot
which contains no voids or dislocation clusters. We further uncover that the interstitial-rich region
in the ingot exhibits no such elastic softening, confirming our previous conclusion that the defects
responsible for the low-temperature elastic softening are the vacancies. We also disclose that the
elastic softening is absent for the ring-like oxidation stacking fault (R-OSF) region of the ingot. The
measured distribution of the vacancy concentration indicates that the minority point defects are
perfectly cancelled by the majority point defects during the CZ crystal growth.
455
Abstract: Characterisation of three-layer dielectric embedded into MDS-structure (Metal-
Dielectric-Silicon) was provided in the dark and under light illumination. In the dark, increasing of
differential capacitance, simultaneously, with variation of differential conductivity of MDSstructures
was detected. In the light strong changing of capacitance part of impedance was firstly
observed, demonstrating decreasing almost to zero values and restoring up to maximal values in
narrow bang of voltage applied. Variation of capacitance exceeds significantly so called dielectric
layer capacitance, what interpreted as carriers exchanging between substrate and electronic states in
SiNx probably due to three-layered kind of its nature.
461
Abstract: The need of an effective control of residual metal content inside the silicon epitaxial
wafers is revamping for CCD and CMOS applications, which are very sensitive to small amount of
heavy metals. The paper will discuss the strengths and the challenges associated to the integrated
use of well known electrical techniques when metals like iron and molybdenum are present in
concentration lower than 1E11 cm^3.
467
Abstract: X-ray absorption fine structure can determine the local structure of most atoms in the
periodic table. The great recent improvements in the performance of synchrotron radiation sources
and techniques and advances in the simulations of the spectra have opened new opportunities,
especially in the study of dilute systems in the soft X-ray range. In this contribution we will show
some recent results that demonstrate how semiconductor physics may greatly benefit from such
progress. In fact, doping or alloying of semiconductors with light elements, that have K absorption
edges in the soft X-ray range, is widely employed to tune semiconductor properties. X-ray
absorption fine structure investigations on such systems can give an important contribution towards
the understanding and optimization of technological processes.
473
Abstract: Thin (90 nm) a-Si:H films on Corning 7059 glass substrates have been crystallized by
120 fs pulses of Ti:sapphire and nanosecond pulse XeCl and KrF excimer lasers. Initial films were
deposited using low-temperature plasma enhanced deposition technique. The structural properties of
the films were characterized using the spectroscopy of Raman scattering, excited by the argon laser
(line 514.5 nm) and using electron microscopy. For the femtosecond pulse treatments the ablation
threshold was found to be some more than 65 mJ/cm2. When pulse energy density was lower than
~30 mJ/cm2 no structural changes were observed. In optimal regimes the films were found to be
fully crystallized with needle grain structure, according to the Raman scattering and electron
microscopy data. Estimates show the pulse energy density was lower than the Si melting threshold,
so non-thermal “explosive” impacts may play some role. The main result in nanosecond XeCl and
KrF laser pulse crystallization is the narrower window between beginning of crystallization and
ablation for KrF laser (wavelength 248 nm) than for the XeCl laser (wavelength 308 nm). So, the
possibility of the femtosecond and nanosecond laser pulses to crystallize a-Si films on non
refractory glass substrates was shown. The results obtained are of great importance for
manufacturing of polycrystalline silicon layers on non-refractory large-scale substrates for giant
microelectronics.
479