A classification scheme for the different forms of implant-related damage which arise upon annealing consisting of five categories is presented. Category I damage is “subthreshold” damage or that which results prior to the formation of an amorphous layer. If the dose is increased sufficiently to result in the formation of an amorphous layer then the defects which form beyond the amorphous/crystalline (a/c) interface are classified as category II (“end of range”) damage. Category III defects are associated with the solid phase epitaxial growth of the amorphous layer. The most common forms of this damage are microtwins, hairpin dislocations and segregation related defects. It is possible to produce a buried amorphous layer upon implantation, If this occurs, then the defects which form when the two a/c interfaces meet are termed category IV (“clamshell”, “zipper”) defects. Finally, category V defects arise from exceeding the solid solubility of the implanted species in the substrate at the annealing temperature. These defects are most often precipitates or dislocation loops.

A systematic analysis of defects in ion-implanted silicon

Molecular dynamics simulation of ion ranges in the 1–100 keV energy range

Ion-beam-induced amorphization in Si has attracted significant interest since the beginning of the use of ion implantation for the fabrication of Si devices. A number of theoretical calculations and experiments were designed to provide a better understanding of the mechanisms behind the crystal-to-amorphous transition in Si. Nowadays, a renewed interest in the modeling of amorphization mechanisms at atomic level has arisen due to the use of preamorphizing implants and high dopant implantation doses for the fabrication of nanometric-scale Si devices. In this paper we will describe the most significant experimental observations related to the ion-beam-induced amorphization in Si and the models that have been developed to describe the process. Amorphous Si formation by ion implantation is the result of a critical balance between the damage generation and its annihilation. Implantation cascades generate different damage configurations going from isolated point defects and point defect clusters in essentially ...

https://www.ele.uva.es/~mmm/papers/2004_Pelaz_JAP_96.pdf

Ion-beam-induced amorphization and recrystallization in silicon

The ion-beam-induced crystalline-to-amorphous phase transition in single crystal ( 6 H) α -SiC has been studied as a function of irradiation temperature. The evolution of the amorphous state has been followed in situ by transmission electron microscopy in specimens irradiated with 0.8 MeV Ne + , 1.0 MeV Ar + , and 1.5 MeV Xe + ions over the temperature range from 20 to 475 K. The threshold displacement dose for complete amorphization in α -SiC at 20 K is 0.30 dpa (damage energy=15 eV atom −1 ). The dose for complete amorphization increases with temperature due to simultaneous recovery processes that can be adequately modeled in terms of a single-activated process. The critical temperature, above which amorphization does not occur, increases with particle mass and saturates at about 500 K. Single crystals of α -SiC with [0001] orientation have also been irradiated at 300 K with 360 keV Ar 2+ ions at an incident angle of 25° over fluences ranging from 1 to 8 Ar 2+ ions nm −2 . The damage accumulation in these samples has been characterized ex situ by Rutherford backscattering spectrometry–channeling (RBS/C) along the [0001] direction, Raman spectroscopy, cross-sectional transmission electron microscopy (XTEM), and mechanical microprobe measurements.

Structure and properties of ion-beam-modified (6H) silicon carbide

Pre-amorphization damage in ion-implanted silicon

Atomic structure of ion implantation damage and the process of amorphization in silicon have been investigated using high‐resolution electron microscopy techniques. The specific damage energy density for crystalline to amorphous transition has been determined to be 6.0×1023 eV/cm3 or 12 eV/atom at 4 K with no annealing. The amorphous regions are produced when the damage energy deposited by the ions exceeds this critical value. Since the damage energy deposited by the ions is a strong function of ion implantation and substrate variables, the formation of amorphous regions and the process of amorphization are strong functions of these variables. The details of atomic structures of amorphous silicon containing microcrystallites and that of amorphous‐crystalline interfaces are presented. The calculations of the mean‐free path between collisions and the energy deposited per atom are found to be consistent with experimental observations on amorphization of silicon. Some results on the projected ranges of low‐en...

Atomic structure of ion implantation damage and process of amorphization in semiconductors

The influence of dose rate on damage accumulation during heavy ion irradiation in Si was investigated. Combined analysis techniques including Rutherford backscattering/channeling spectrometry (RBS) and transmission electron microscopy (TEM) were used to characterize the nature and amount of residual damage. For room temperature irradiations, the amount of residual damage increased with increasing dose rate over the entire range investigated. However, no dependence was observed for cryogenic irradiations. These results are shown to be in good agreement with a model which assumes that damage is nucleated homogeneously.

Dose rate dependence of damage clustering during heavy ion irradiation in Si

Excimer laser mixing of nickel overlayers on silicon carbide

The phenomenon of explosive recrystallization has been studied in Si+ and Cu+ implanted amorphous silicon layers by electron microscopy and Rutherford backscattering techniques (RBS). Cross‐section and plan‐view electron microscopy techniques (TEM) have been used to obtain a detailed characterization of microstructures associated with the explosive mode of recrystallization. RBS and analytical TEM studies on segregation of copper provided information on the mechanism of explosive recrystallization involving a thin liquid film interposed between crystallized and uncrystallized regions.

D. Fathy

Papers

Atomic structure of ion implantation damage and process of amorphization in semiconductors

Dose rate dependence of damage clustering during heavy ion irradiation in Si

Excimer laser mixing of nickel overlayers on silicon carbide

Explosive recrystallization during pulsed laser irradiation