Features of the Pulsed Treatment of Silicon Layers Implanted with Erbium Ions

Abstract—The formation of thin-film solid solutions of erbium in silicon and synthesis of erbium silicides were performed using continuous implantation of silicon with erbium ions followed by pulsed ion-beam treat- ment. Structural and optical properties of formed Si:Er layers were studied by Rutherford backscattering, trans- mission electron microscopy, and low-temperature photoluminescence. The dependences of erbium redistribu- tion, the microstructure of Si:Er layers, and their photoluminescence in the near-IR region on the erbium con- centration and pulsed treatment conditions were determined

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

О ТЕМПЕРАТУРНОЙ ЗАВИСИМОСТИ ФОТОЛЮМИНЕСЦЕНЦИИ КВАНТОВЫХ ТОЧЕК КРЕМНИЯ

A model of radiative and nonradiative transitions in silicon quantum dots is presented that describes the temperature dependence of photoluminescence of ion-synthesized ensembles of Si nanocrystals in SiO2. The four−level scheme of transitions is considered taking into account thermally activated processes and exchange splitting of the ground state of excited exciton to triplet and singlet sublevels, transitions from which are responsible for the luminescence. The expression for temperature dependence of the monochromatic photoluminescence components that is in agreement with a number of analogous dependencies from literature is derived on the basis of solution of a system of kinetic equations. The obtained expression describes adequately experimental results of the given work and allows to determine the splitting value for the exciton state in dependence on the energy of emitted photons, i.e. the nanocrystal size.Представлена модель излучательных и безызлучательных переходов в квантовых точках кремния, которая описывает температурную зависимость фотолюминесценции ионно-синтезированных массивов нанокристаллов Si в SiO2. Рассмотрена четырехуровневая схема переходов, учитывающая термоактивированные процессы и обменное расщепление основного энергетического состояния экситона в нанокристалле кремния на триплетный и синглетный уровни, переходы с которых в основное состояние ответственны за люминесценцию. На основе стационарного решения системы кинетических уравнений, описывающих заселенность уровней, получено выражение для температурной зависимости монохроматических составляющих фотолюминесценции, которое удовлетворительно описывает экспериментальные результаты. Найдены и сравнены с литературными данными величины расщепления энергетического состояния экситона в зависимости от энергии излучаемых фотонов

Formation of light-emitting Si:Er layers by ion implantation and pulsed annealing

In this work the formation of Si:Er solid solutions and erbium silicide layers by means of Er ion implantation and pulsed annealing by nanosecond ion and laser beams was carried out. The dependence of Er atoms redistribution in Si and also the microstructure and phase composition of Si:Er layers on the implanted fluence and regimes of pulsed annealing was determined. It is shown that Si:Er layers obtained using pulsed and thermal treatments have photoluminescent properties in the near infrared region at 77 K. These properties are manifested by the intensive signals at Л = 1.13 and 1.54 ц т

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

Structure, impurity composition, and photoluminescence of mechanically polished layers of single-crystal silicon

The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a silicon single crystal using irradiation, plastic deformation, or heat treatment has been considered a possible approach to the design of silicon-based light-emitting structures in the near infrared region. Defects were introduced into silicon plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged silicon layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and x-ray fluorescence. Optical properties of the defects were studied at 77 K using photoluminescence (PL) in the near infrared region. It has been shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at temperatures of 850 to 1000°C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by copper atoms, which are gettered from the crystal bulk, make the predominant contribution to PL spectra. © 2005 Pleiades Publishing, Inc

Phase transitions in erbium-doped silicon exposed to laser radiation

The dynamics of phase transitions induced by nanopulsed ruby laser radiation (80 nsec, 2 J/cm2 ) both in silicon layers doped with erbium ions and in those containing doped erbium and oxygen have been studied by an optical probing method. It is shown that the reflectivity behavior of structures under pulsed irradiation is governed by phase transitions (melting and rystallization) of implanted silicon and also by interference effects at the interfaces of the resulting phases. It is established that the profiles of erbium distribution change under nanosecond laser irradiation and that the dopant is forced out to the surface due to a segregation effect at small implantation doses. As the implanatation dose increases, diffusion deep into the sample tends to prevail over segregation. A considerable increase in the photoluminescence peak intensity at 0.81 eV is found after both the pulsed laser processing and thermal post-annealing of doped samples as opposed to spectra of samples subjected either to thermal annealing or to pulsed laser irradiation

Features of the Pulsed Treatment of Silicon Layers Implanted with Erbium Ions

Abstract—The formation of thin-film solid solutions of erbium in silicon and synthesis of erbium silicides were performed using continuous implantation of silicon with erbium ions followed by pulsed ion-beam treat- ment. Structural and optical properties of formed Si:Er layers were studied by Rutherford backscattering, trans- mission electron microscopy, and low-temperature photoluminescence. The dependences of erbium redistribu- tion, the microstructure of Si:Er layers, and their photoluminescence in the near-IR region on the erbium con- centration and pulsed treatment conditions were determined