Boron channeling implantations in silicon: Modeling of electronic stopping and damage accumulation

Abstract

Channeling implantations of 20 keV boron into silicon have been performed with doses between 1013 and 1016 cm−2 in the [100], [110], and [211] direction, and parallel to a (111) plane. Simulations using an empirical electronic stopping model agree very well with the experimental results. The model has been obtained considering a large number of random and channeling implantations published in the literature. It contains a nonlocal and an impact parameter dependent part with the nonlocal fraction increasing with energy. Moreover, a computationally efficient damage accumulation model is presented which takes point defect recombination into account. It is found that due to interactions within a recoil cascade only 1/8 of the generated damage is stable, and that damage saturation takes place at a concentration of 4×1021 cm−3. Comparison of simulations and experiments indicates that displaced atoms reside on random positions rather than on tetrahedral interstitial sites in the silicon lattice.

Partitioning to elastic and inelastic processes of the energy deposited by low energy ions in silicon detectors

“…This was first recognized by Hobler et al [24]. It was used in their IMSIL code and further improved by Tian [25].…”

Improved physical models for advanced silicon device processing

“…To take into account such effect, advanced BCA simulators include the feedback of accumulated damage for the next cascades [40,42,[127][128][129][130]. Figure 11 shows KMC simulation results of the evolution of the a-layer thickness with dose [131], compared with experimental data from Maszara et al [132], for 150 keV Si implants at 82 K. There is an initial fast increase of the a/c interface depth with dose until a given depth is reached, and then, the increase is very slow.…”

Enhanced phenomenological models of ion channeling contribution to doping profiles in crystals

“…The validation of the 9-parameter high-dose implantation model of section 5 has been performed for two families of experimental doping profiles [32,40] that cover substantially different energies, ions and targets (see figures 5 and 6). It has been assumed that for each profile of this family all model parameters except for the experimentally declared value of ion fluence φ are equal.…”

“…To validate our models, a large array of experimental and simulation data available in publications [32][33][34][35][36][37][38][39][40] has been used. Their model description was carried out by means of the LevenbergMarquardt method of NLSq fitting.…”

“…Experimental SIMS data picked up from various sources [32][33][34][35][36][37][38] were fitted using both the 8-parameter model developed in section 4, and the standard 9-parameter "dual Pearson" model. It is clear that both models are qualitatively applicable to fit all the data.…”