A.V. Zverev

3D-model of epitaxial growth on porous {111} and {100} Si surfaces

A 3D Monte Carlo model of epitaxial and annealing processes on (111) and (100) surfaces of diamond-like crystals was developed. Simulations of epitaxial growth on porous Si(111) and Si(100) surfaces using this model were carried out. Distinct relief is formed over sealing pores due to diffusion differences on these surfaces. A smooth solid layer is formed on the (111) surface whereas pyramidal pits faceted by (111) planes are created over pores on the (100) surface. The deposited dose necessary for pore sealing is one order of magnitude greater on the Si(100) than on the Si(111) surface.

A Monte Carlo simulation of the processes of nanostructure growth: The time-scale event-scheduling algorithm

The SilSim3D program package is developed to conduct Monte Carlo simulations of the kinetics of growth, evaporation, and annealing of thin layers on solid substrates on the basis of an original algorithm of scheduling events on a real time scale. The model allows the simulation of various nanoelectronic technological processes in multicomponent physical and chemical systems of more than 107 particles in time intervals comparable with the actual experimental times. The initial stages of atomic layer deposition and the growth of silicon nanowhiskers are simulated as an example.

Experimental studies in quantum cryptography

A short survey on experimental works in quantum cryptography is presented. We describe experimental setups that were designed in the Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, for quantum key distribution through an air space and along a fiber-optic communication line. The results of the study of quantum efficiency parameters, probability of afterpulse appearance, and noise levels for different operation modes of InGaAs-InP avalanche photodiodes are presented.

Lattice Monte Carlo model of SiOx layers

A kinetic Monte Carlo model of amorphous SiOx layers has been developed on the basis of a partially filled diamond-like lattice with allowance for different valences of silicon and oxygen. In the starting model layers of stoichiometric composition SiO2, about 50% of lattice sites are randomly occupied by silicon and oxygen atoms, which tend to form chains of vertex-sharing tetrahedra SiO4 upon long-term model annealing. The amount of perfectly coordinated atoms reaches ∼65% after short-term annealing and slowly increases with time, indicating the formation of a metastable state. In the most ordered final state, more than 90% of atoms are perfectly coordinated. The presence of excess silicon in SiOx layers increases the fraction of perfectly coordinated oxygen atoms up to 95%. As the SiO2 matrix tends to the final ordered state, excess silicon atoms assemble to form nanoclusters.

Monte Carlo Simulation of Porous Layers Sintering

Kinetics of porous layer evolution during high-temperature annealing was investigated by Monte Carlo simulation. Sintering process of spongy one-component films with randomly distributed pores was studied. Layers with porosity from 20% to 50% with simple cubic and diamond-like lattices were under examination. Sintering rate was demonstrated to be non-monotone in time for any film porosity and different lattice coordination number. Metastable states of the system, dependent on time and temperature of annealing process, were revealed. Estimation of annealing time necessary to reach the definite sintering level under changes of annealing temperature was suggested.

Monte Carlo simulation of steps behavior on Si(111) surface during sublimation

Investigation of steps behavior on vicinal (111) surface during sublimation was carried out using 3D-model of diamond-like crystal. Step width periodic variations predicted by Schwoebel were found by modeling. Diamond-like crystal structure results in the asymmetry in atom fluxes to the upper or lower terraces, with the sign of asymmetry depending on the step structure. The essential effect of vacancies created on terraces on migration length of atoms was revealed.

Causes of the stability of three-bilayer islands and steps on a Si (111) surface

AbstractThe initial stages of growth of Ge and Si layers on a singular Si (111) surface result in an unusual morphology of the growth surface if the layers are deposited at a low rate; i.e., triangular islands with a height of as much as three atomic layers are formed. A simulation based on the Monte Carlo method has been used to show that an additional barrier with a height of 0.5–0.6 eV, serving to incorporate atoms into dimerized bonds at the edges of the triangular islands, brings about enhanced growth of the islands in relation to their height and a change in the triangles’ orientation. According to the suggested hypothesis, the increase in the islands’ height and the limitation of their height to three bilayers are due to the effect of the edge dimers, whose orientation changes when the height of a step perpendicular to the

A fiber quantum communication system based on an autocompensation optical circuit

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