The evolution of the defect structure and electric properties of the oxygenimplanted silicon samples subjected by thermal treatment in the temperature range from 700 to 1100 C is investigated using transmission electron microscopy (TEM) and space charge spectroscopy. It is established that embedded positive charge of oxygen precipitates (OPs) decreases inversely proportional to their size. This fact gives evidence about localization of the charge in thin nonstoichiometric shell of OP. Annealing at 700 C results in the formation of nanosized defects and in an inhomogeneous electric structure of the implanted region: the embedded positive charge is localized in the near-surface vacancy-rich part of the implanted region, whereas the strongly compensated layer is formed in self-interstitial-rich deepest part of the implanted region.

Oxygen precipitates (OPs) formed by the annealing of oxygen implanted silicon samples at diverse temperatures in the ranges from 700°C to 1100°С have been investigated with capacitance-voltage and transmission electron microscopy techniques. An increase of the OP sizes with the increasing temperature was found to accompany with a decrease of the OP embedded positive charge being inversely proportional to the formers. The obtained result showed that the positive charge is localized in SiOx shell of predominantly stoichiometric OP core.

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Defect structure, electrical properties and defect-related luminescence (DRL) of light emitting diodes (LED) with the active defect-rich region produced by oxygen implantation and a subsequent multistep annealing of silicon wafers were investigated. It was found that defect-rich regions possess an embedded positive charge in both n-and p-type of the samples whose origin was ascribed to oxygen precipitates (OP). The presence of that charge in the implanted region of p-based LED gave rise to the apparent conductivity type conversion and to a significant increase of free electron concentration in n-based LEDs. A significant difference in the shape and in the excitation dependence of luminescence spectra as well as in the properties of DLTS signals was found between p-and n-type samples. From an analysis of the obtained data the DRL band centered at 0.79 eV was ascribed to small OPs segregated at dislocations whose filling with the holes hinders optical transitions via dislocation-related states at 0.805 eV and the broad DRL band at energies higher than 0.81 eV was ascribed to large OPs.

A new method has been developed for the epitaxial growth of cadmium sulfide CdS films in a metastable cubic phase on silicon substrates with a buffer layer of epitaxial silicon carbide by atomic layer deposition. This CdS phase is achieved due to the low growth temperature (~ 180 ℃). The cubic phase was identified by both X-ray diffraction (XRD) and spectral ellipsometry due to the fact that the main peak of CdS absorption is split into two peaks in the hexagonal phase (4.9 eV and 5.4 eV) and is a singlet in the cubic phase (5.1 eV).