[en] Radiation-resistant silicon-on-insulator structures were produced by N⁺ ion implantation into thermally grown SiO₂ film and subsequent hydrogen transfer of the Si layer to the nitrogen-implanted substrate under conditions of vacuum wafer bonding. Accumulation of the carriers in the buried SiO₂ was investigated as a function of fluence of nitrogen ions in the range (1-6)x10¹⁵ cm² and as a function of total radiation dose ranging from 10⁴ to 10⁷ rad (Si). It was found that the charge generated near the nitrided bonding interface was reduced by a factor of four compared to the thermal SiO₂/Si interface.

[en] The photoluminescence and photoluminescence excitation spectra of SiO_2 films implanted with high (3 at %) Si"+-ion doses are studied in relation to the temperature of postimplantation annealing. It is shown that two photoluminescence bands with peaks at 2.7 and 2 eV are dominant in the spectra. As the annealing temperature is increased, the relation between the intensities of the 2.7 and 2 eV bands changes in favor of the former one. Both of the photoluminescence bands have their main excitation peak at the energy 5.1 eV. The excitation spectrum of the ∼2-eV band exhibits also peaks at 3.8 and 4.6 eV. It is concluded that, in the implanted SiO_2 films, the orange photoluminescence band originates from radiative transitions between levels of centers associated with a deficiency of oxygen (≡Si–Si≡ or =Si:) and the levels of nonbridging oxygen (≡Si–O•)

[en] Electrical properties of silicon-on-insulator (SOI) structures with buried SiO₂ layer implanted with nitrogen ions are studied in relation to the dose and energy of N⁺ ions. It is shown that implantation of nitrogen ions with doses >3 × 10¹⁵ cm⁻² and an energy of 40 keV brings about a decrease in the fixed positive charge in the oxide and a decrease in the density of surface stares by a factor of 2. An enhancement of the effect can be attained by lowering the energy of nitrogen ions. The obtained results are accounted for by interaction of nitrogen atoms with excess silicon atoms near the Si/SiO₂ interface; by removal of Si-Si bonds, which are traps of positive charges; and by saturation of dangling bonds at the bonding interface of the SOI structure.

[en] The hydrophilicity of surfaces and the bonding energy of silicon and sapphire wafers at the temperature of joining 50°C are studied. It is established that heating of the Si and Al₂O₃ wafers to 50°C is accompanied by an increase in the degree of hydrophilicity of the wafer surfaces. The effect is attributed to improvement in the surface purity due to the desorption of impurity atoms into vacuum and to an increase in the density of dangling bonds. It is found that the bonding energy of silicon and sapphire wafers joined at a temperature of 50°C and upon further heating in the range 100–250°C is higher compared to the bonding energy of wafers joined at room temperature. The activation energy of the growth of the bonding energy is determined. It is found that this activation energy is 0.57 eV.

[en] The special features of photoluminescence spectra of silicon-on-insulator structures implanted with hydrogen ions are studied. An increase in the photoluminescence intensity with increasing hydrostatic pressure P during annealing and the formation of narrow periodic photoluminescence peaks in the spectral range from ∼500 to 700 nm are revealed for the structures annealed at P > 6 kbar. It is shown that the fine structure of the photoluminescence spectra correlates with the slowing-down of hydrogen effusion from the implanted samples and with the suppression of the formation of hydrogen microbubbles in the surface layer. These processes promote the formation of an optical resonator, with the mirrors formed by the 'silicon-on-insulator-air' and 'silicon-on-insulator-SiO₂' interfaces and with the optically active layer formed by hydrogen ion implantation and subsequent annealing

[en] The nucleation of the crystalline Ge phase in SiO_xN_y films implanted with Ge⁺ ions with the energy 55 keV to doses of 2.1 × 10¹⁵–1.7 × 10¹⁶ cm^–2 and then annealed at a temperature of T_a = 800–1300°C under pressures of 1 bar and 1–12 kbar is studied. From analysis of the Raman spectra, it is concluded that amorphous Ge precipitates increase in size upon hydrostatic compression at a temperature of 1000°C. Raman scattering at optical phonons localized in Ge nanocrystals is observed only after annealing of the samples with the highest content of implanted atoms at a temperature of 1300°C. In the photoluminescence spectra, a peak is observed at the wavelength ∼730 nm. The peak is considered to be the manifestation of the quantum-confinement effect in nanocrystals ∼3 nm in size.

[en] The Raman spectra of SiO₂ films containing InSb spherical nanocrystals produced by ion-beam synthesis are studied. TO- and LO-like modes in the spectra of the InSb nanocrystals are detected at frequencies of 187 and 195 cm^–1, respectively. The shift of these modes to high frequencies with respect to the corresponding frequencies in InSb bulk crystals is analyzed from the viewpoint of the influence of the quantum-confinement effect, strains in nanocrystals, the surface phonon frequency, and scattering at the frequency corresponding to stretched anion–cation modes at the surface of polar spherical nanocrystals. The position of the 195-cm^–1 mode corresponds to LO phonons in InSb nanocrystals hydrostatically compressed in the SiO₂ matrix at pressures of about 10 kbar. The 187-cm^–1 mode corresponds to resonance at the Fröhlich frequency.

[en] The growth of Ge nanocrystals in SiO₂ films is studied in relation to the dose of implanted Ge⁺ ions and the annealing temperature at a pressure of 12 kbar. It is established that the dependences of the nanocrystal dimensions on the content of Ge atoms and the annealing time are described by the corresponding root functions. The nanocrystal radius squared is an exponential function of the inverse temperature. The dependences correspond to the model of the diffusion-controlled mechanism of nanocrystal growth. From the temperature dependence of the nanocrystal dimensions, the diffusion coefficient of Ge in SiO₂ at a pressure of 12 kbar is determined: D = 1.1 × 10^–10 exp(–1.43/kT). An increase in the diffusion coefficient of Ge under pressure is attributed to the change in the activation volume of the formation and migration of point defects. Evidence in favor of the interstitial mechanism of the diffusion of Ge atoms to nanocrystal nuclei in SiO₂ is reported.

[en] By means of Rutherford backscattering spectrometry, electron microscopy, and energy-dispersive X-ray spectroscopy, the distribution and interaction of In and As atoms implanted into thermally grown SiO₂ films to concentrations of about 1.5 at % are studied in relation to the temperature of subsequent annealing in nitrogen vapors in the range of T = 800–1100°C. It is found that annealing at T = 800–900°C results in the segregation of As atoms at a depth corresponding to the As⁺-ion range and in the formation of As nanoclusters that serve as sinks for In atoms. An increase in the annealing temperature to 1100°C yields the segregation of In atoms at the surface of SiO₂ with the simultaneous enhanced diffusion of As atoms. The corresponding diffusion coefficient is D_As = 3.2 × 10^–14 cm² s^–1.

[en] The properties of germanium implanted into the SiO₂ layers in the vicinity of the bonding interface of silicon-on-insulator structures are studied. It is shown that, under conditions of high-temperature (1100 deg. C) annealing, germanium nanocrystals are not formed, while the implanted Ge atoms segregate at the Si/SiO₂ bonding interface. It is established that, in this case, Ge atoms are found at sites that are coherent with the lattice of the top silicon layer. In this situation, the main type of traps is the positive-charge traps; their effect is interpreted in the context of an increase in the surface-state density due to the formation of weaker Ge-O bonds. It is found that the slope of the drain-gate characteristics of the back MIS transistors increases; this increase is attributed to an increased mobility of holes due to the contribution of an intermediate germanium layer formed at the Si/SiO₂ interface