Mass Of Implanted Ions Research Articles

Effect of Implanted Ion Mass and Incident Energy on Defect and Ion Depth-Distributions in Ion-Implanted Si

Effect of Implanted Ion Mass and Incident Energy on Defect and Ion Depth-Distributions in Ion-Implanted Si

Modeling of the ion mass effect on transient enhanced diffusion: Deviation from the “+1” model

The influence of ion mass on transient enhanced diffusion (TED) and defect evolution after ion implantation in Si has been studied by atomistic simulation and compared with experiments. We have analyzed the TED induced by B, P, and As implants with equal range and energy: TED increases with ion mass for equal range implants, and species of different mass but equal energy cause approximately the same amount of TED. Heavier ions produce a larger redistribution of the Si atoms in the crystal, leading to a larger excess of interstitials deeper in the bulk and an excess of vacancies closer to the surface. For high-mass ions more interstitials escape recombination with vacancies, are stored in clusters, and then contribute to TED. TED can be described in terms of an effective “+n” or “plus factor” that increases with the implanted ion mass.

Oxygen incorporation in polyethylene and polypropylene implanted with F+, As+ and I+ ions at high dose

Samples of PolyPropylene (PP) and PolyEthylene (PE) implanted with 150 keV F+, As+ and I+ ions with a dose of 1×1015 cm−2 were studied using standard Rutherford Back Scattering (RBS) technique. No fluorine atoms above the present RBS detection limit were observed in the ion-implanted polymers. The measured depth profiles of As and I atoms are significantly broader than those predicted by the TRIM code for pristine polymers. The differences can be explained by stepwise polymer degradation due to ion bombardment. Massive oxidation of the ion-implanted polymers is observed. The oxidation rate and the resulting oxygen depth profile depend strongly on the polymer type and implanted ion mass. In the samples implanted with F+ ions, an uniformly oxidized layer is built up with a mean oxygen concentration of 15 at.%. In the samples implanted with As+ and I+ ions, a non-uniform oxygen depth distribution is observed with two concentration maxima on the sample surface and in a depth correlated with implanted ion range.

Molecular Ion S2+ and SiFn+ implantations into GaAs

AbstractMolecular ion S2+ and SiFn+ implantations into GaAs have been investigated to form very thin active layers. After implantation, the transient annealing (TA) and furnace annealing (FA) were used. The measurements of activation efficiency, mobility, carrier concentration profiles and PL spectra were carried out. The experiments show that after TA, the activation efficiency, mobility and carrier distribution are almost the same between samples implanted with S+ at an energy of 50KeV to a dose of 3×1013cm−2 and S+2 at 100KeV to 1.5×1013cm−2. It shows that the damage of S2-implanted samples can be removed by TA, and a very thin active layer can be formed by the implantation of S2+ at 50KeV. For SiFn-implanted samples, the activation efficiency and mobility. decrease with increase of the implanted ion mass. As+ co-implantation into SiF-implanted samples has been used to improve both activation efficiency and mobility. After comparison with the properties of the SiFt implantation, S2+implantation is more acceptable to form thin active layers.

Silicon amorphization during heavy ion implantation-part II

Abstract The silicon amorphization process during heavy ion implantation is considered. Expressions are derived for the critical doses, ϕ0 and ϕcr for silicon amorphization at low and room implantation temperatures. respectively. Silicon amorphization doses are calculated for Kr+, Xe+, Nd+, Yb+, and Hg+ ions. ϕ0 is shown to decrease by a factor of 1.5 to 2 in the energy range 10 to 100 keV, and with further increase in energy ϕ0 is shown to remain constant. At low energiesE ≲ 40 keV critical doses for silicon amorphization depend weakly on ion mass and implantation temperature (in the range 100 to 300 K). The value of ϕcr/ϕ0 increases with energy and decreases with increasing implanted ion mass. The results of calculations agree well with experimental data.

Ion implantation and low-temperature epitaxial regrowth of GaAs

Channeling and transmission electron microscopy have been used to investigate the parameters that govern the extent of damage in ion-implanted GaAs and the crystal quality following capless furnace annealing at low temperature (∼400 °C). The implantation-induced disorder showed a strong dependence on the implanted ion mass and on the substrate temperature during implantation. When the implantation produced a fully amorphous surface layer the main parameter governing the regrowth was the amorphous thickness. Formation of microtwins after annealing was observed when the initial amorphous layer was thicker than 400 Å. Also, the number of extended residual defects after annealing increased linearly with the initial amorphous thickness and extrapolation of that curve predicts good regrowth of very thin (<400 Å) GaAs amorphous layers produced by ion implantation. A model is presented to explain the observed features of the low-temperature annealing of GaAs.

Production of radiation defects in silicon at different temperatures

Abstract Results of backscattering measurements of radiation damage in ion implanted silicon layers are presented and compared with the results of optical and electrical investigations. The influence of several implantation parameters on amount and depth distribution of radiation damage produced at low temperatures can be described by the energy deposited into nuclear processes. In this case the depth profile of refractive index change correlates with the damage distribution. With increasing temperature energy deposited into ionization processes becomes more and more important and the kind of defect nucleation changes. Both depth distributions of radiation damage and properties of the produced defects are different from those found after implantation at low temperatures. There are strong correlations between modified defect production characteristics at a given temperature and the mass of implantedions.