Lattice sites of implanted Fe in Si

Influence of n+ and p+ doping on the lattice sites of implanted Fe in Si

“…We then fitted each pattern again by considering these three fractions in the proportion that best decreased the χ 2 of fit. We note that the near-BC sites from this study can be interpreted as near-S sites observed in previous studies on Fe in Si 25,26 . In fact, new simulations that include more displacements from S towards BC sites (step width 0.0588Å vs. 0.1470Å in Refs.…”

“…While small deviations can be explained by statistical errors in the analysis, there are also some systematic effects: (1) After the implantation, a small fraction of 59 Fe is located in heavily damaged surroundings or sites of very low crystal symmetry (random sites), so that the sum of all regular and identified site fractions becomes smaller than 100%; (2) When some of the 59 Fe moves towards the surface compared with the assumed implantation depth profile, the intensity of the channeling effects is increased as well as the corresponding fitted fractions. This explains why the sum may reach values above 100% at intermediate annealing temperatures 25 ; if diffusing, 59 Fe accumulates at the surface (out-diffusion) or escapes to the bulk of the wafer (in-diffusion), channeling effects are lost, the random fraction increases, and the sum drops to values below 100% 25 . This is what supposedly happens at the highest annealing temperatures.…”

“…The two-dimensional experimental data were fitted using calculated emission channeling patterns, obtained with the so-called many beam approach 25 . The calculated emission channeling patterns include the emission probability of the substitutional (S), hexagonal (H), tetrahedral (T), bond-centered (BC), anti-bonding (AB), split (SP) and the so-called Y and C sites, as well as < 111 >, < 100 > and < 110 > displacements between these positions.…”

“…In our previous EC study 25 , no significant changes were observed in the 59 Fe lattice position when using different types of Si for resistivities above ∼ 0.01 Ωcm. However, this was attributed to the possibility that the Fermi level, following implantation into low or moderately doped Si, is most likely close to the mid-gap position, due to the fact that the concentration of implantation defects is, by several orders of magnitude, larger than those of n-or p-type dopants.…”

“…EC has already been applied to study the lattice sites of 59 Fe in low and moderately doped n-and p-type Si 25,26 . The results showed 59 Fe in three different positions: ideal substitutional (S), displaced substitutional (near-S) and displaced tetrahedral interstitial (near-T) sites.…”