X-ray and optical characterization of β-FeSi₂layers formed by pulsed ion-beam treatment

Abstract

β-FeSi2 layers were formed on Si by means of high-dose Fe+ implantation into Si(100) at 300 K followed by nanosecond pulsed ion-beam treatment (PIBT) of the implanted layers. It is shown that PIBT leads to the formation of a mixture of two phases (FeSi and β-FeSi2) with a strained state of the silicide crystal lattice. Subsequent short-duration thermal annealing at 800 °C for 20 min results in a decrease of the lattice strains and in the complete transformation of the FeSi phase into the β-FeSi2 phase, with the production of a highly textured layer with the [110] orientation. The results of the optical absorption measurements indicate the formation of a direct band gap structure with the optical gap Eg~0.83 eV and the Urbach tail width E0~0.22 eV.

Preparation of Iron and Gold Silicide Nanodomains on Silicon (111) by the Reaction of Gold, Iron−Gold Core−Shell, and Alloy Nanoparticles with Triethylsilane

“…This process is explained based on the established literature of gold-silicon chemistry: Gold and silicon have a relatively low eutectic temperature; at higher temperature, the iron-gold mixture remains as a liquid eutectic alloy. It is reasonable to expect To the best of our knowledge, no complete experimental XRD spectrum of β-FeSi 2 nanoparticles has been presented in the literature (26,(62)(63)(64)(65)(66)(67)(68)(69)(70). When the sample is annealed at 800 °C with triethylsilane, the (023), ( 440), ( 006), (262), and (535) atomic reflections disappear (Figure 7b ii).…”

“…However, only 11−12 XRD reflections of β-FeSi 2 are observed on silicon (111) substrate (either from core-shell or alloy nanoparticles). To the best of our knowledge, no complete experimental XRD spectrum of β-FeSi 2 nanoparticles has been presented in the literature ,− . When the sample is annealed at 800 °C with triethylsilane, the (023), (440), (006), (262), and (535) atomic reflections disappear (Figure b ii).…”

Structural properties of Fe ion implanted and ruby laser annealed Si layers

“…An alternative to furnace annealing of whole Si wafers could be pulsed treatment of the implanted Si layers by powerful laser, electron and ion beams that are characterized by localization (in area and depth) and short duration (typically <1 µs) of processing. At present, a limited number of works have been published relating to pulsed treatments of the Fe-Si system in order to form iron silicide films on Si [6][7][8][9]. In [6], it was shown that treatment of epitaxial β-FeSi 2 films on an Si(111) substrate with 25 ns ruby laser pulses with an energy density of about 0.5 J cm −2 led to a transformation from the orthorhombic β-FeSi 2 phase to the cubic γ -FeSi 2 one.…”

“…Earlier, we studied the formation of iron silicide films in Fe-implanted Si layers subjected to pulsed ion-beam treatment (C + , H + ) [8] or Nd : YAG laser (λ = 1.06 µm) irradiation [9]. We showed that pulsed ion-beam treatment of the implanted Si layers with an energy density of more than 1 J cm −2 leads to the formation of single-phase, textured and stressed β-FeSi 2 films.…”

Structural and optical properties of magnetron sputtered and pulsed beam annealed Ge/Si layers

“…Compared to traditional pulsed laser annealing (PLA) pulsed ion-beam treatment (PIBT) allows one to modify deeper layers (up to 1 μm) without significant surface damage due to more uniform energy deposition by ion beams within projected range and independence on optical parameters of irradiated layers. Such treatments were successfully used for epitaxial regrowth of metal silicide and Ge thin films on Si [15] and implanted Si layers [16,17].…”