Anton Bondarenko

Electrical levels of dislocation networks in p- and n-type Si

The results of deep level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS) investigations on directly bonded n- and p-type silicon wafers with small twist misorientation angles ranging from 1 to 5 degrees are presented and discussed. Both shallow and deep levels in the upper half of a band gap are found and a good correspondence between the DLTS and MCTS data on n- and p-type samples was established. The dependence of DLTS-peak magnitude on twist and tilt misorientation angles (density of dislocations) was investigated and the origin of different levels is suggested.

Dislocation Structure, Electrical and Luminescent Properties of Hydrophilically Bonded Silicon Wafer Interface

The dislocation-related luminescence (DRL) in the vicinity of D1 band (0.8 eV) in hydrophilically bonded n- and p-type silicon wafers is investigated by means of recently developed pulsed trap refilling enhanced luminescence technique (Pulsed-TREL). The shallow and deep dislocation related electronic states in both upper and lower part of the band gap are determined and characterized by means of DLTS. Among those traps we have established ones which directly participate in D1 DRL. We have shown that D1 luminescence goes via shallow dislocation related states (SDRS) located close to the conduction and valence bands with thermal activation energy of about 0.1 eV whereas deep levels do not participate in D1 DRL. The model explaining the fact how the 0.8 eV luminescence may go through levels which interlevel energy is at least 0.97 eV in terms of Coulomb interaction between ionized SDRS is suggested.

Identification of dislocation-related luminescence participating levels in silicon by DLTS and Pulsed-CL profiling

We present a study of the dislocation network that occurs in the space charge region of a Schottky diode, by means of DLTS and our recently developed cathodoluminescent (CL) technique called Pulsed-CL. The details of the Pulsed-CL technique are provided. We establish a correspondence between the CL spectra of dislocation-related luminescence in silicon in the vicinity of the so-called D1 band and levels determined from DLTS measurements. The centres responsible for the 815 meV CL component are related to dislocations cores while the centres responsible for the 795 meV CL component are related to some defects outside of the dislocation cores.

Predator Odor Destabilizes the Cell Genome of the Mouse Bone Marrow

The effect of urine chemosignals of domestic male cats (Felis catus L.) on the stability of the bone marrow cell genome and corticosterone level in blood plasma of recipient mice (Mus musculus L.) is studied. It is demonstrated that a two-hour sniffing of volatile chemosignals leads to an increase in the frequency of bone marrow cells with damaged DNA, while 24 h exposure to chemosignals leads to an increase of chromosomal aberrations frequency in these cells. Thus, the effect of genomic instability induction in bone marrow cells of house mice by predator’s chemosignals is for the first time demonstrated in the work. At the same time, no increase in the corticosterone level is detected in the blood plasma either 30 or 60 min after the beginning of the exposure to the chemosignals of cat urine (CU). The physiological factors contributing to DNA damages accumulation in bone marrow cells, as well as the long-term consequences of the effect of these chemosignals on the genome stability, are discussed.

Band-Like Behavior of Localized States of Metal Silicide Precipitate in Silicon

Deep-level transient spectroscopy (DLTS) investigations of energy levels of charge-carrier traps associated with precipitates of metal silicide often show that they behave not like localized monoenergetic traps but as a continuous density of allowed states in the bandgap with fast carrier exchange between these states, so-called band-like behavior. This kind of behavior was ascribed to the dislocation loop bounding the platelet, which in addition exhibits an attractive potential caused by long-range elastic strain. In previous works, the presence of the dislocation-related deformation potential in combination with the external electric field of the Schottky diode was included to obtain a reasonable fit of the proposed model to experimental data. Another well-known particular property of extended defects—the presence of their own strong electric field in their vicinity that is manifested in the logarithmic kinetics of electron capture—was not taken into account. We derive herein a theoretical model that takes into account both the external electric field and the intrinsic electric field of dislocation self-charge as well as its deformation potential, which leads to strong temporal variation of the activation energy during charge-carrier emission. We performed numerical simulations of the DLTS spectra based on such a model for a monoenergetic trap, finding excellent agreement with available experimental data.

Transient luminescence induced by electrical refilling of charge carrier traps of dislocation network at hydrophilically bonded Si wafers interface

Dislocation network (DN) at hydrophilically bonded Si wafers interface is placed in space charge region (SCR) of a Schottky diode at a depth of about 150 nm from Schottky electrode for simultaneous investigation of its electrical and luminescent properties. Our recently proposed pulsed traps refilling enhanced luminescence (Pulsed-TREL) technique based on the effect of transient luminescence induced by refilling of charge carrier traps with electrical pulses is further developed and used as a tool to establish DN energy levels responsible for D1 band of dislocation-related luminescence in Si (DRL). In present work we do theoretical analysis and simulation of traps refilling kinetics dependence on refilling pulse magnitude (Vp) in two levels model: shallow and deep. The influence of initial charge state of deep level on shallow level occupation-Vp dependence is discussed. Characteristic features predicted by simulations are used for Pulsed-TREL experimental results interpretation. We conclude that only shallow (∼0.1 eV from conduction and valence band) energetic levels in the band gap participate in D1 DRL.