18,423 research outputs found
Dielectric relaxation and Charge trapping characteristics study in Germanium based MOS devices with HfO2 /Dy2O3 gate stacks
In the present work we investigate the dielectric relaxation effects and
charge trapping characteristics of HfO2 /Dy2O3 gate stacks grown on Ge
substrates. The MOS devices have been subjected to constant voltage stress
(CVS) conditions at accumulation and show relaxation effects in the whole range
of applied stress voltages. Applied voltage polarities as well as thickness
dependence of the relaxation effects have been investigated. Charge trapping is
negligible at low stress fields while at higher fields (>4MV/cm) it becomes
significant. In addition, we give experimental evidence that in tandem with the
dielectric relaxation effect another mechanism- the so-called Maxwell-Wagner
instability- is present and affects the transient current during the
application of a CVS pulse. This instability is also found to be field
dependent thus resulting in a trapped charge which is negative at low stress
fields but changes to positive at higher fields.Comment: 27pages, 10 figures, 3 tables, regular journal contribution (accepted
in IEEE TED, Vol.50, issue 10
On entropy, specific heat, susceptibility and Rushbrooke inequality in percolation
We investigate percolation, a probabilistic model for continuous phase
transition (CPT), on square and weighted planar stochastic lattices. In its
thermal counterpart, entropy is minimally low where order parameter (OP) is
maximally high and vice versa. Besides, specific heat, OP and susceptibility
exhibit power-law when approaching the critical point and the corresponding
critical exponents respectably obey the Rushbrooke
inequality (RI) . Their analogues in percolation,
however, remain elusive. We define entropy, specific heat and redefine
susceptibility for percolation and show that they behave exactly in the same
way as their thermal counterpart. We also show that RI holds for both the
lattices albeit they belong to different universality classes.Comment: 5 pages, 3 captioned figures, to appear as a Rapid Communication in
Physical Review E, 201
Multiphoton excitations in vibrational rotational states of diatomic molecules in intense electromagnetic field
A theory is presented and a calculational procedure is outlined for evaluating transition amplitudes of multiphoton excitations of vibrational-rotational levels in diatomic molecules. This theory can be utilized in studying behavior of molecules in intense electromagnetic fields
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