electroluminescence has been studied in silicon light-emitting diodes containing oxygen precipitates at temperatures of 40–300 K. Oxygen ion implantation and multistage anneals are used for fabrication of the diodes. Over all temperature range, spectra are well approximated by one Lorentz and four Gaussian curves. Lines of dislocation-related luminescence D1–D4 (the D1 line is described by Lorentz curve) and oxygen precipitates (OPs) are present in the spectra. At temperature variation, peak positions of the D1, OP, and D2 lines coincide with temperature dependence of the forbidden gap width reduced by values of 356, 330, and 303 meV respectively. Build and quenching areas are observed on temperature dependences of the electroluminescence intensities of the D1, OP, and D2 lines, the activation energies of the processes are determined, and reasons of their appearance are discussed.

Electroluminescence has been studied in silicon light-emitting diodes containing oxygen precipitates at temperatures of 40-300 K. Oxygen ion implantation and multistage anneals are used for fabrication of the diodes. Over all temperature range, spectra are well approximated by one Lorentz and four Gaussian curves. Lines of dislocation-related luminescence D1-D4 (the D1 line is described by Lorentz curve) and oxygen precipitates (OPs) are present in the spectra. At temperature variation, peak positions of the D1, OP and D2 lines coincide with temperature dependence of the forbidden gap width reduced by values of 356, 330 and 303 meV respectively. Build and quenching areas are observed on temperature dependences of the electroluminescence intensities of the D1, OP and D2 lines, the activation energies of the processes are determined, and reasons of their appearance are discussed.

Silicon light-emitting diodes with dislocation-related electroluminescence have been studied at room temperature. For the fabrication of the light-emitting diode structures, a well-known method for the formation of dislocation-related luminescence centers during anneals of silicon with a high oxygen concentration in a flow of argon was modified by introducing a preliminary O+ ion implantation and carrying out a final anneal in a chlorine-containing atmosphere. In the electroluminescence spectra, the D1 dislocation-related luminescence line dominates at currents less than <150 mA and the near-band-edge luminescence line starts to dominate with increasing current. The electroluminescence excitation efficiency for the D1 center is 3.3·10-20 cm2·s at room temperature. Keywords:: Light-emitting diodes, dislocation-related luminescence, silicon, oxygen precipitates.

Effect of the pump power on the photoluminescence intensity for dislocation-related luminescence centers is studied in p-type silicon containing oxygen precipitates. Oxygen precipitates are induced as a result of three-stage annealing used for formation of a getter for fast diffusing impurities in microelectronics technology while D1 and D2 dislocation-related luminescence centers were produced during subsequent annealing in a flow of argon at 1000oC. The photoluminescence excitation efficiencies for the D1 and D2 lines were measured at a temperature of liquid helium. Keywords: dislocation-related luminescence, silicon, oxygen precipitates, photoluminescence excitation efficiency.

Effect of the pump power on the photoluminescence intensity for dislocation-related luminescence centers is studied in p-type silicon containing oxygen precipitates. Oxygen precipitates are induced as a result of three-stage annealing used for formation of a getter for fast diffusing impurities in microelectronics technology while D1 and D2 dislocation-related luminescence centers were produced during subsequent annealing in a flow of argon at 1000°С. The photoluminescence excitation efficiencies for the D1 and D2 lines were measured at a temperature of liquid helium.

Dislocation-related photoluminescence is studied in silicon wafers with and without oxygen-ion implantation after multistage heat treatment, which is used in microelectronics to form an internal getter, and final annealing at 1000°C in a chlorine-containing atmosphere. In the sample without oxygen implantation, the dislocation-related luminescence line D1 dominates and its intensity exceeds by more than an order of magnitude that for another dislocation-related luminescence line D2. With increasing temperature, the intensity of the D1 line first increases and then decreases. In the implanted sample, the intensities of the D1 and D2 lines grow. For both the lines, only temperature quenching of their intensities is observed. The energies of quenching and buildup of the intensities of dislocation-related photoluminescence lines are determined. Possible reasons for the observed effects are discussed.

Silicon light-emitting diodes with dislocation-related electroluminescence have been studied at room temperature. For the fabrication of the light-emitting diode structures, a well-known method for the formation of dislocation-related luminescence centers during anneals of silicon with a high oxygen concentration in a flow of argon was modified by introducing a preliminary O+- ion implantation and carrying out a final anneal in a chlorine-containing atmosphere. In the electroluminescence spectra, the D1 dislocation-related luminescence line dominates at currents less than 150 mA and the near-band-edge luminescence line starts to dominate with increasing current. The electroluminescence excitation efficiency for the D1 center is 3.3 · 10-20 cm2 · s at room temperature.

The structure and luminescence properties of Czochralski-grown n-Si samples implanted with oxygen ions have been comprehensively analyzed using photoluminescence and transmission electron microscopy (TEM). A high oxygen concentration (5 × 1019 cm–3) in a layer at a depth of 0.3–0.8 µm was obtained in the implanted material. The samples have been annealed according to the multistage technique, including low-temperature (650/800°C) and high-temperature (1000°C) stages, to obtain oxygen precipitates and a system of various extended defects. The structure of the dislocation-photoluminescence spectrum is determined by the features of interaction of dislocations with oxygen during annealing. It is established that decoration of dislocations with oxygen precipitates leads to quenching the D1 and D2 lines. The strong D1 line is due to “pure” (without oxygen precipitates) dislocations. Free amorphous oxygen precipitates emit at a wavelength of 1476 nm.

Dislocation-related photoluminescence is studied in unimplanted and implanted with oxygen ions silicon wafers after multistage heat treatment, used for the formation of internal getter in microelectronics, and final annealing at 1000°С in a chlorine-containing atmosphere. In unimplanted sample, the dislocation-related luminescence line D1 dominates and its intensity is more than one order of magnitude in comparison with another dislocation-related luminescence line D2. With increasing temperature, an intensity of the D1 line increases and then decreases. In implanted sample, the intensities of the D1 and D2 lines increase. For both the lines, temperature quenching of their intensities is observed only. The energies of quenching and increase of the intensities of dislocation-related photoluminescence lines are determined. Possible reasons of observed effects are discussed.

Silicon light-emitting diodes with luminescence associated with (113) defects have been fabricated using implantation of 350 keV oxygen ions at the dose of 3.7∙1014 cm-2 and subsequent annealing at 700ᵒC for 1 h in a chlorine-containing atmosphere. Electroluminescence was studied in wide ranges of temperature and an excitation power. The line associated with (113) defects dominates in all the spectra. The temperature dependence of the line intensity depends on the excitation power in the range of low temperatures: an increase of the intensity with activation energy of 25 meV is observed at low current density and, with the increasing current density, a rise of the intensity is not observed. At higher temperatures, a decrease of the intensity with activation energy of 59 meV occurs regardless of a current density. With the increasing temperature, the peak of the line shifts by the same energy as the forbidden gap width, while the half width of the line grows linearly.

Silicon light-emitting diodes with luminescence associated with (113) defects are fabricated by the implantation of 350-keV oxygen ions at a dose of 3 . 7 × 10 14 cm –2 and subsequent annealing at 700°C for 1 h in a chlorine-containing atmosphere. The electroluminescence is studied in wide temperature and excitation-power ranges. The line associated with the (113) defects is dominant in all the spectra. The temperature dependence of the line intensity depends on the excitation power at low temperatures: an increase in the intensity with an activation energy of 25 meV is observed at low current densities and no rise in the intensity is observed with increasing current density. At higher temperatures, an intensity with an activation energy of 59 meV is quenched irrespective of the current density. With increasing temperature, the peak of the line of the (113) defect shifts by the same energy as the energy-gap width, whereas the half width of the line grows linearly.

The concentration profiles of defects produced in structures upon the implantation of nitrogen ions into GaAs epitaxial layers with an uncovered surface and that covered with an AlN film and subsequent annealing are studied. The ion energies and the implantation doses are chosen so that the nitrogen-atom concentration profiles coincided in structures of both types. Rutherford proton backscattering spectra are measured in the random and channeling modes, and the concentration profiles of point defects formed are calculated for the samples under study. It is found that the implantation of nitrogen ions introduces nearly the same number of point defects into structures of both types, and the formation of an AlN film by ion-plasma sputtering is accompanied by the formation of an additional number of defects. However, the annealing of structures of both types leads to nearly the same concentrations of residual defects.

The influence exerted by the conditions of the post-implantation annealing of silicon implanted with germanium ions on how luminescence centers are formed is studied. Measurements by the technique of the Rutherford backscattering of medium- and high-energy ions demonstrates that implantation with 1-MeV germanium ions at a dose of 1.5 × 1014 cm–2 does not lead to the amorphization of single-crystal silicon. It is found that subsequent high-temperature annealing of the implanted samples in a chlorine-containing atmosphere at a temperature of 1100°C for 0.5–1.5 h gives rise to so-called D1 and D2 dislocation-related luminescence lines with wavelengths of 1.54 and 1.42 μm. With increasing annealing duration, the intensity of the D1 line decreases and that of D2 remains constant, but the D1 line dominates in all the spectra. The possible factors responsible for a decrease in the intensity of the D1 line and, in particular, the diffusion of germanium atoms and the formation of a silicon–germanium solid solution are discussed.

AbstractThe concentration profiles of defects produced in structures upon the implantation of nitrogen ions into GaAs epitaxial layers with an uncovered surface and that covered with an AlN film and subsequent annealing are studied. The ion energies and the implantation doses are chosen so that the nitrogen-atom concentration profiles coincided in structures of both types. Rutherford proton backscattering spectra are measured in the random and channeling modes, and the concentration profiles of point defects formed are calculated for the samples under study. It is found that the implantation of nitrogen ions introduces nearly the same number of point defects into structures of both types, and the formation of an AlN film by ion-plasma sputtering is accompanied by the formation of an additional number of defects. However, the annealing of structures of both types leads to nearly the same concentrations of residual defects.

The implantation of Czochralski-grown p-type silicon with 1-MeV germanium ions at a dose of 2.5 × 1014 cm–2 does not lead to the amorphization of single-crystal silicon. Under subsequent high-temperature annealing, electrically active acceptor centers are transformed. Their concentration and special distribution depend on the annealing temperature. The possible factors determining how these centers are formed are discussed.

AbstractThe influence exerted by the conditions of the post-implantation annealing of silicon implanted with germanium ions on how luminescence centers are formed is studied. Measurements by the technique of the Rutherford backscattering of medium- and high-energy ions demonstrates that implantation with 1-MeV germanium ions at a dose of 1 . 5 × 10^14 cm^–2 does not lead to the amorphization of single-crystal silicon. It is found that subsequent high-temperature annealing of the implanted samples in a chlorine-containing atmosphere at a temperature of 1100°C for 0.5–1.5 h gives rise to so-called D1 and D2 dislocation-related luminescence lines with wavelengths of 1.54 and 1 . 42 μm. With increasing annealing duration, the intensity of the D1 line decreases and that of D2 remains constant, but the D1 line dominates in all the spectra. The possible factors responsible for a decrease in the intensity of the D1 line and, in particular, the diffusion of germanium atoms and the formation of a silicon–germanium solid solution are discussed.

AbstractThe implantation of Czochralski-grown p -type silicon with 1-MeV germanium ions at a dose of 2 . 5 × 10^14 cm^–2 does not lead to the amorphization of single-crystal silicon. Under subsequent high-temperature annealing, electrically active acceptor centers are transformed. Their concentration and special distribution depend on the annealing temperature. The possible factors determining how these centers are formed are discussed.

AbstractStructural defects formed in epitaxial GaAs layers as a result of 250-keV N^+ ion implantation to doses within 5 × 10^14–5 × 10^16 cm^–2 have been studied by the X-ray diffraction (XRD) and transmission electron microscopy techniques. No amorphization of the ion-implanted layer took place in the entire dose range studied. The implantation to doses of 5 × 10^14 and 5 × 10^15 cm^–2 led to the appearance of an additional peak on XRD curves, which was related to the formation of a stressed GaAs layer with positive deformation arising due to the formation of point-defect clusters. The implantation to a dose of 5 × 10^16 cm^–2 led to the formation of a dense structure of extended defects in the implanted layer, which was accompanied by the relaxation of macrostresses to the initial state.

Structural defects formed in epitaxial GaAs layers as a result of 250-keV N+ ion implantation to doses within 5 × 1014–5 × 1016 cm–2 have been studied by the X-ray diffraction (XRD) and transmission electron microscopy techniques. No amorphization of the ion-implanted layer took place in the entire dose range studied. The implantation to doses of 5 × 1014 and 5 × 1015 cm–2 led to the appearance of an additional peak on XRD curves, which was related to the formation of a stressed GaAs layer with positive deformation arising due to the formation of point-defect clusters. The implantation to a dose of 5 × 1016 cm–2 led to the formation of a dense structure of extended defects in the implanted layer, which was accompanied by the relaxation of macrostresses to the initial state.