A model for the formation of amorphous Si by ion bombardment
IBM1
01 Jan 1970-Radiation Effects and Defects in Solids (Taylor & Francis Group)-Vol. 6, Iss: 1, pp 27-32
TL;DR: In this paper, a phenomenological model was proposed to account for the variation of the critical dose required to produce a continuous amorphous layer by ion bombardment with ion, target, temperature, and, with minor additional assumptions, dose rate.
Abstract: The effective annealing of ion implantations in Si is aided by the formation of continuous amorphous layer. The amorphous layer regrows epitaxially at 500–600°C and incorporates the dopant in an electrically active, uncompensated form. A phenomenological model is proposed which, with adjustable parameters, accounts for the variation of the critical dose required to produce a continuous amorphous layer by ion bombardment with ion, target, temperature, and, with minor additional assumptions, dose rate.
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TL;DR: The role of implantation defects, the effect of annealing, concentration dependent effects, and optical activation are discussed and compared for different Er-doped thin film photonic materials.
Abstract: Erbium doped materials are of great interest in thin film integrated optoelectronic technology, due to their Er3+ intra-4f emission at 1.54 μm, a standard telecommunication wavelength. Er-doped dielectric thin films can be used to fabricate planar optical amplifiers or lasers that can be integrated with other devices on the same chip. Semiconductors, such as silicon, can also be doped with erbium. In this case the Er may be excited through optically or electrically generated charge carriers. Er-doped Si light-emitting diodes may find applications in Si-based optoelectronic circuits. In this article, the synthesis, characterization, and application of several different Er-doped thin film photonic materials is described. It focuses on oxide glasses (pure SiO2, phosphosilicate, borosilicate, and soda-lime glasses), ceramic thin films (Al2O3, Y2O3, LiNbO3), and amorphous and crystalline silicon, all doped with Er by ion implantation. MeV ion implantation is a technique that is ideally suited to dope these materials with Er as the ion range corresponds to the typical micron dimensions of these optical materials. The role of implantation defects, the effect of annealing, concentration dependent effects, and optical activation are discussed and compared for the various materials.
1,089 citations
Pacific Northwest National Laboratory1, University of Michigan2, Royal Institution3, Lawrence Livermore National Laboratory4, Massachusetts Institute of Technology5, Kyushu University6, Institute for Transuranium Elements7, Pennsylvania State University8, Los Alamos National Laboratory9, University of Cambridge10, Australian Nuclear Science and Technology Organisation11, Oak Ridge National Laboratory12
TL;DR: A comprehensive review of the state-of-the-art of radiation effects in crystalline ceramics that may be used for the immobilization of high-level nuclear waste and plutonium is provided in this article.
Abstract: This review provides a comprehensive evaluation of the state-of-knowledge of radiation effects in crystalline ceramics that may be used for the immobilization of high-level nuclear waste and plutonium. The current understanding of radiation damage processes, defect generation, microstructure development, theoretical methods, and experimental methods are reviewed. Fundamental scientific and technological issues that offer opportunities for research are identified. The most important issue is the need for an understanding of the radiation-induced structural changes at the atomic, microscopic, and macroscopic levels, and the effect of these changes on the release rates of radionuclides during corrosion.
834 citations
01 Jan 1972
TL;DR: In this article, a qualitative description of the damage produced by an implanted ion is presented, followed by a partial inventory of the basic defects that are found in ion-implanted silicon, where theoretical predictions are compared to a variety of experimental data.
Abstract: Radiation damage is produced in a crystalline target whenever a moving ion transfers sufficient energy to a target atom to displace it from its lattice site. For conditions of practical importance in ion implantation, the radiation damage produced by the injected ions is severe, and the crystal must be carefully Annealed if the chemical effects of the implanted ions are to dominate the residual damage. The purpose of this paper is to review work that has been performed over the past several years in an effort to understand implantation-produced damage and its annealing characteristics, especially in silicon. The subject is developed as follows. A qualitative description of the damage produced by an implanted ion is presented in Section I, followed by a partial inventory of the basic defects that are found in ion-implanted silicon (Section II). The structure of individual damage clusters produced by both heavy and light ions is then described in Section III, where theoretical predictions are compared to a variety of experimental data. This is followed with a section on the depth distribution of defects and damage clusters (Section IV); and the paper is then concluded with a section on the annealing characteristics of implantation-produced damage (Section V). The development is organized to give primary emphasis to those facts and ideas that are essential for applications of ion implantation in the fabrication of MOS and junction devices in silicon. A future paper will review the state of the art in compound semiconductors.
672 citations
02 May 2000-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: A number of models have been developed to describe the various amorphization processes and the effects of temperature on the kinetics of amorphisation as mentioned in this paper, and these models contain a number of parameters relating to irradiation-assisted and thermal recovery processes.
Abstract: A number of models have been developed to describe the various amorphization processes and the effects of temperature on the kinetics of amorphization. These models are reviewed and in some cases further developed. In general, these models contain a number of parameters relating to irradiation-assisted and thermal recovery processes, which make their application to existing data sets challenging. Nonetheless, general aspects of the models yield insights into the rate-limiting processes controlling the kinetics of amorphization within a given temperature regime. Several examples are used to illustrate features of the models and to highlight differences in behavior.
396 citations
TL;DR: A comprehensive understanding of radiation effects in zircon, ZrSiO4, over a broad range of time scales (0.5 h to 570 million years) has been obtained by a study of natural ZIRcon, Pu-doped Zircon and ion-beam irradiated Zrcon as discussed by the authors.
Abstract: A comprehensive understanding of radiation effects in zircon, ZrSiO4, over a broad range of time scales (0.5 h to 570 million years) has been obtained by a study of natural zircon, Pu-doped zircon, and ion-beam irradiated zircon. Radiation damage in zircon results in the simultaneous accumulation of both point defects and amorphous regions. The amorphization process is consistent with models based on the multiple overlap of particle tracks, suggesting that amorphization occurs as a result of a critical defect concentration. The amorphization dose increases with temperature in two stages (below 300 K and above 473 K) and is nearly independent of the damage source (α-decay events or heavy-ion beams) at 300 K. Recrystallization of completely amorphous zircon occurs above 1300 K and is a two-step process that involves the initial formation of pseudo-cubic ZrO2.
361 citations
References
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TL;DR: In this paper, the orientation dependence of the backscattered yield of 1.0-MeV helium ions has been used to investigate the lattice characteristics of silicon and germanium implanted at room temperature with 40-...
Abstract: The orientation dependence of the backscattered yield of 1.0-MeV helium ions has been used to investigate the lattice characteristics of silicon and germanium implanted at room temperature with 40-...
255 citations
01 Mar 1968
TL;DR: Theoretical and experimental work pertinent to the problem of predicting impurity distribution profiles in ion-implanted material are reviewed in Part II as mentioned in this paper, together with the characteristics of a number of interesting semiconductor devices that have already been fabricated by ion implantation.
Abstract: Ion implantation in semiconductors provides a doping technique with several potential advantages over more conventional doping methods. Among the most important of these are: 1) the ability to introduce into a variety of substrates precise amounts of nearly any impurity element desired; 2) the ability to control doping profiles in three dimensions by modulating the energy, current, and position of the ion beam; and 3) the possibility of avoiding certain undesirable effects that accompany the high-temperature diffusion process. Ion implantation can also be used in conjunction with other fabrication techniques to produce device structures that no one process can produce simply by itself. Current research in the field is directed toward several problems that must be solved before the full impact of ion implantation on semiconductor technology can be soundly predicted. In particular, it is necessary to be able to predict the distribution profiles of the implanted ions accurately, to know which crystalline sites the implanted ions occupy, to know the nature of the damage centers that are introduced by the implantation process, and to determine the extent to which these defects can he removed by appropriate annealing procedures. Theoretical and experimental work pertinent to the problem of predicting impurity distribution profiles in ion-implanted material are reviewed here. A review of current research on the other problems listed will be given in Part II, together with the characteristics of a number of interesting semiconductor devices that have already been fabricated by ion implantation.
224 citations
TL;DR: The implantation and annealing behavior of several Group III (Ga, In, Tl) and Group V (As, Sb, Bi) dopants in silicon has been investigated by studying the orientation dependence of the scattering yield of a 1.0-MeV He+ beam.
Abstract: The implantation and annealing behavior of several Group III (Ga, In, Tl) and Group V (As, Sb, Bi) dopants in silicon has been investigated by studying the orientation dependence of the scattering yield of a 1.0‐MeV He+ beam. This orientation dependence (``channeling'') provides quantitative information on the location of the foreign atoms in the lattice, and also on the amount of lattice disorder introduced by the implantation. The behavior of the Group V elements is relatively simple. In hot (350°–450°C) implants and also in annealed room‐temperature implants, the dopant atoms are located mostly on substitutional sites, even for implant doses exceeding equilibrium solubility values by 1–2 orders of magnitude. Upon subsequent anneal, no evidence of precipitation is observed below ∼900°C. The behavior of the Group III elements is much more complex. In addition to a substitutional component, a significant fraction of the implanted atoms are located in the regular interstitial holes along the (111) atomic rows. The substitutional/interstitial ratio in hot implants is usually 1:1, except in the case of Tl implants where, on annealing to ∼575°C, a pure interstitial component is observed. Furthermore, the subsequent annealing behavior is found to depend markedly not only on the particular Group III ion, but also on the implantation temperature. Various factors that may contribute to the Group III behavior are discussed. Preliminary ion implantation studies with other elements (Cd, Sn, Te, Xe, Cs, and Au) in silicon have been included.
160 citations
TL;DR: In this article, the g value, line shape, and linewidth of an ESR signal in Si layers which have been damaged by ion implantation of Si, P, or As at room temperature are found to be identical to those of the electron states observed in amorphous Si films prepared by rf sputtering.
Abstract: The g value, line shape, and linewidth of an ESR signal in Si layers which have been damaged by ion implantation of Si, P, or As at room temperature are found to be identical to those of the electron states observed in amorphous Si films prepared by rf sputtering. Interference phenomena observed in the optical absorption spectra allow a determination of the depth to which the Si has been damaged by the energetic heavy ions. These two techniques together provide a new tool for investigating lattice disorder in ion‐implanted Si layers.
153 citations
TL;DR: In this paper, structural measurements of Si and Ge were compared and interpreted in terms of the annealing of identified defects, and it was shown that the center temperatures for both Ge and Si were approximately 0.35 and 0.5 times the melting temperature.
Abstract: Structural measurements of neutron and ion damage annealing in Si and Ge are compared and interpreted in terms of the annealing of identified defects. Either or both of two prominent isochronal annealing stages above room temperature in neutron irradiated Si are exhibited by X-ray, electron microscope, infrared, and electrical measurements. It is shown that the same two annealing stages are observed in Rutherford scattering measurements of ion implanted Si. Two similar prominent annealing stages are also observed for structural measurements of neutron and ion irradiated Ge. For both Ge and Si the center temperatures for the two annealing stages are approximately 0.35 and 0.5 times the melting temperature. The annealing kinetics and activation energies for the lower temperature stage in Si are correlated with the kinetics and activation energies obtained by analyzing previously reported results on the effects of the substrate temperature and the ion irradiation rate. From a comparison of the time ...
138 citations