Dislocation-related Luminescence Research Articles

Silicon Light-Emitting Diodes with Dislocation-Related Luminescence Fabricated with Participation of Oxygen Precipitates

Silicon Light-Emitting Diodes with Dislocation-Related Luminescence Fabricated with Participation of Oxygen Precipitates

The Excitation Efficiency for Dislocation-Related Luminescence Centers in Silicon with Oxygen Precipitates

The Excitation Efficiency for Dislocation-Related Luminescence Centers in Silicon with Oxygen Precipitates

Температурная зависимость дислокационной электролюминесценции в кремниевых светодиодах с кислородными преципитатами

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 Luminescence Fabricated with Participation of Oxygen Precipitates

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.

The Excitation Efficiency for Dislocation-Related Luminescence Centers in Silicon with 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.

Эффективность возбуждения центров дислокационной люминесценции в кремнии с кислородными преципитатами

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.

Кремниевые светодиоды с дислокационной люминесценцией, сформированные с участием кислородных преципитатов

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.

Effect of Additional Implantation with Oxygen Ions on the Dislocation-related Luminescence in Silicon-containing Oxygen Precipitates

Effect of Additional Implantation with Oxygen Ions on the Dislocation-related Luminescence in Silicon-containing Oxygen Precipitates

Characteristic emission from quantum dot-like intersection nodes of dislocations in GaN

Freshly introduced a-screw dislocations in gallium nitride are an effective source of ultraviolet radiation, characterized by intense emission of narrow luminescence doublet lines in the spectral range of 3.1-3.2 eV. Furthermore, an additional narrow spectral line with an energy of 3.3 eV has been found at the points of intersection of such dislocations, where extended dislocation nodes were formed. In this communication, we report on the spectral properties of the characteristic luminescence of such nodes, which were obtained for the (0001) gallium nitride samples with dislocations introduced by nanoindentation. The spectral position of the dislocation-related luminescence doublet experiences a redshift with increasing distance from the indentation site. It follows the spectral shift of the excitonic near-bandgap emission, associated with stress relaxation. The luminescence of the intersection points exhibits a similar tendency. At certain local positions, its doublet fine structure is observed, which has a spectral linewidth of the order of or even less than that of the exciton. In this case, the spectral splitting between components of the doublet varies irregularly depending on the position of the exciton (i.e., on the mechanical stress). We see a clear indication of quantum dot-like emission. The fine structure of the luminescence of the intersection points can be easily explained by the energy dependence of emission on their size, as well as on their density, in particular, by the formation of paired nodes, which were previously observed in experiments in a transmission electron microscope.

Влияние дополнительной имплантации ионов кислорода на дислокационную люминесценцию кремния, содержащего кислородные преципитаты

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.

Temperature dependence of dislocation-related photoluminescence (D1) of self-implanted silicon subjected to additional boron implantation

The goal of this work is the qualitative and quantitative interpretation of experimental data obtained for the effect of additional boron ion implantation on the temperature dependence of dislocation-related luminescence (D1 line) of self-implanted silicon. This goal is motivated by the need in development of effective light emitter for silicon-based optoelectronics. The model explaining the previously established improvement of the D1 line temperature dependence is suggested and supported by computer calculations based on a set of kinetic equations taking into account the radiative and nonradiative electron transitions between energy levels.

Comparative Study of Optical and Electrical Properties of Grown-In and Freshly Introduced Dislocations in GaN by SEM Methods

Electrical and optical properties of grown-in and freshly introduced dislocations in GaN have been studied by the electron beam induced current and cathodoluminescence methods. It is observed that the recombination properties of grown-in and freshly introduced basal plane and threading dislocations are comparable. That allows to assume the intrinsic nature of dislocation recombination activity in GaN. It is demonstrated that the recombination properties of basal plane dislocations weakly depend on their type. The behavior of dislocation-related luminescence at 3.1 eV is more complex. It can be observed not in all GaN crystals even when dislocations are introduced in the similar conditions. Besides, it is not observed on basal plane and threading grown-in dislocations. This luminescence is not produced by freshly introduced basal plane dislocations. These observations can be explained assuming that the dislocation-related luminescence is associated with point defects generated by dislocations gliding in pyramidal or prismatic slip planes.

Towards an efficient light-emitting source based on self-implanted silicon with dislocation-related luminescence

The regularities of ion synthesis of dislocation-related luminescence centers in silicon have been investigated. By varying the conditions of additional irradiation with boron ions, as well as the conditions of subsequent annealing, we obtain an increase in the luminescence intensity, as well as a shift of maximum of the temperature dependence towards higher temperatures. It was found for the first time that, for the highest used dose of boron ions (3·1017 cm-2) and additional heat treatment at 830 °C, it is possible to get the measurable luminescence at room temperature.

Unusual Polarization Dependence of Dislocation‐Related Luminescence in n‐GaN

Dislocation‐related luminescence (DRL) in n‐GaN from a‐screw dislocations introduced by cracking or nanoindentation is investigated using cathodoluminescence (CL) and polarization optical spectroscopy. In strain‐free samples with rare array of parallel dislocations, the polarization direction one of two DRL spectral components is directed parallel while for other components, it is inclined under the angle of about 40° to the dislocation line that is attributed to the theoretically predicted different orientations of chemical bonds in the cores of N and Ga partials of the dissociated a‐screw dislocation. DRL investigations near the indentation prick reveal the presence of two doublet broadbands polarized at 60° with respect to each other that is caused by two crossing families of screw dislocations observed with CL.

Asymmetry of the Atomic Core Structure of Dissociated a‐Screw Dislocation in GaN Probed by Polarization Optical Spectroscopy

The a‐screw dislocation related luminescence (DRL) in n‐GaN is investigated with polarization optical spectroscopy. An unusual difference in the polarization directions of two DRL spectral components is observed: directed parallel or inclined at an angle of about 40° to the dislocation line. As a tentative explanation, that property is proposed to be due to the theoretically predicted different orientations of chemical bonds in the cores of N and Ga partials of the dissociated a‐screw dislocation.

Defect structure and properties of Zn diffusion doped Si after swift Xe ion irradiation

The electronic and optical properties of Si doped by Zn diffusion have been studied for a long time. Recently the defect structure and properties of n-Si (111) compensated by Zn during high-temperature diffusion annealing with subsequent quenching were investigated. The large-scale rod-like defects with μ-sizes have been observed. These defects were connected with Zn precipitates or/and dislocations. In the present paper we study the modification of defect structure and properties of Zn diffusion doped Si after swift heavy ion (SHI) irradiation. The SHI irradiation is known to lead to the formation of latent tracks (nanometer-sized disordered regions around ion trajectory) in many semiconductor and oxide crystals. It was established that the craters with a size of about 100nm surrounded by hillocks are fixed on the Si surface. The traces of dislocation group along Xe ion beam direction were revealed on Si surface. The small-angle boundaries and interstitial-type planar defects have appeared. After Xe ion irradiation with a fluence of 5×1012 cm−2 the number of radiating centres in dislocation core increasing so, that increasing the dislocation-related luminescence (DRL) from the lines D1 and D2. When the Xe ion irradiation fluence is increased to a value of 1×1014 cm−2 the DRL in the Si sample is almost extinguished.

Extended core structure and luminescence of a-screw dislocations in GaN

Straight segments of a-screw dislocations introduced by scratching of basal (0001) of intentionally undoped low-ohmic GaN radiate a doublet of narrow luminescent lines in the spectral region at about 3.1-3.2 eV while the dislocation intersection points possess luminescence band at about 3.3 eV. Transmission electron microscopy reveals that the dislocation cores are dissociated into two 300 partials separated by stacking fault (SF) ribbon with the width of 4-6 nm width and that the dislocation nodes contain extended SF of sizes of 25-30 nm. Dislocation-related luminescence (DRL) is ascribed to exciton bound by the states of partial dislocation cores and of SF quantum well. The increase of the SF lateral sizes is assumed to cause the DRL spectral shift between straight dislocations and their nodes due to the system dimensionality transition from 1D to 2D respectively.

Dislocation-Related Photoluminescence in Silicon Implanted with Germanium Ions

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.

Дислокационная фотолюминесценция в кремнии, имплантированном ионами германия

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.

Effect of Boron Impurity on the Light-Emitting Properties of Dislocation Structures Formed in Silicon by Si+ Ion Implantation

The effect of boron implantation on the light-emitting properties of dislocation structures formed in silicon by Si+ ion implantation with subsequent annealing is studied. It is shown that the implantation of B+ ions has a significant effect on the dislocation-related luminescence intensity, spectrum and the temperature dependence of the D1-band intensity. It is found that the temperature dependence is nonmonotonous and involves two regions, in which the D1-band intensity increases with increasing temperature and has two well-pronounced maxima at 20 K and 60–70 K. The maximum at 20 K is associated with the morphological features of the dislocation structure under study, whereas the maximum at 60–70 K is associated with the additional implantation of the boron impurity into the dislocation region of the samples. It is established that the intensities of the experimentally observed maxima and the position of the high-temperature maximum depend on the implanted boron concentration.