Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by implant. In order to study mechanisms of TED, transmission electron microscopy measurements implantation damage were combined with experiments using doping marker structures grown molecular-beam epitaxy (MBE). Damage nonamorphizing implants at doses ranging 5×1012 1×1014/cm2 evolves into a distribution {311} interstitial agglomerates initial...

The transient supersaturation in a system undergoing Ostwald ripening is related to the cluster formation energy ${E}_{\mathrm{fc}}$ as function of size $n$. We use this relation study energetics self-interstitial clusters Si. Measurements enhanced diffusion B Si-implanted Si are used determine $S(t)$, and inverse modeling derive ${E}_{\mathrm{fc}}(n)$. For with $n>15$, ${E}_{\mathrm{fc}}\ensuremath{\approx}0.8\mathrm{eV}$, close fault ${113}$ defects. $n<10$, typically 0.5 eV higher,...

A comprehensive model for B implantation, diffusion and clustering is presented. The model, implemented in a Monte Carlo atomistic simulator, successfully explains predicts the behavior of under wide variety implantation annealing conditions by invoking formation immobile precursors clusters, prior to onset transient enhanced diffusion. also includes usual mechanisms Si self-interstitial kick-out. cluster precursors, such as BI2 (a atom with two self-interstitials) form during or very early...

A new atomistic approach to Si device process simulation is presented. It based on a Monte Carlo diffusion code coupled binary collision program. Besides diffusion, the includes recombination of vacancies and interstitials, clustering re-emission from clusters, trapping interstitials. We discuss typical room-temperature implant at 40 keV, 5×1013 cm−2 into (001)Si, followed by high temperature (815 °C) anneal. The damage evolves an excess interstitials in form extended defects with total...

A comprehensive model of the nucleation, growth, and dissolution B clusters in Si is presented. We analyze activation implanted on basis detailed interactions between defects Si. In model, nucleation requires a high interstitial supersaturation, which occurs damaged region during implantation at early stages postimplant anneal. grow by adding to preexisting clusters, resulting complexes with content. As annealing proceeds supersaturation decreases, emit interstitials, leaving small stable...

The evaporation of {311} self-interstitial clusters has recently been linked to the phenomenon transient enhanced diffusion in silicon. A theory cluster is described, based on first-order kinetic equations. It shown give a good account data over range temperatures. simultaneously explains several unexpected features diffusion, including apparently steady level enhancement during its duration, and dependence duration implant energy dose. binding used match agreement with molecular dynamics...

Carbon often appears in Si concentrations above its solubility. In this article, we propose a comprehensive model that, taking diffusion and clustering into account, is able to reproduce variety of experimental results. Simulations have been performed by implementing Monte-Carlo atomistic simulator. The initial path for included the consistent with observations regarding formation dissolution substitutional C–interstitial C pairs (Cs–Ci). addition, carbon profiles at 850 900 °C carbon-doping...

Abstract The hydrogen bonds involving sulfur in the furfuryl mercaptan monohydrate are compared with interactions originating from hydroxyl group alcohol. dimers water were created a supersonic jet expansion and characterized using microwave spectroscopy supporting molecular orbital calculations. In alcohol–water, single isomer is observed, which molecule forms an insertion complex two simultaneous to alcohol (O−H⋅⋅⋅O w ) ring oxygen (O −H⋅⋅⋅O r ). When replaced by thiol mercaptan–water,...

The temporal evolution of the electrically active B fraction has been measured experimentally on implanted Si, and calculated using atomistic simulation. An implant 40 keV, 2×1014 cm−2 was examined during a postimplant anneal at 800 °C. results show low activation (∼25%) for short times (⩽10 s) that slowly increases with time (up to 40% 1000 s), in agreement model proposed by Pelaz et al. [Appl. Phys. Lett. 74, 3657 (1999)]. Based results, we conclude clustering occurs presence high...

The influence of ion mass on transient enhanced diffusion (TED) and defect evolution after implantation in Si has been studied by atomistic simulation compared with experiments. We have analyzed the TED induced B, P, As implants equal range energy: increases for implants, species different but energy cause approximately same amount TED. Heavier ions produce a larger redistribution atoms crystal, leading to excess interstitials deeper bulk an vacancies closer surface. For high-mass more...

A detailed study corroborates that the Ti(<sc>iii</sc>)-mediated reductive deoxygenation of activated -OH proceeds <italic>via</italic> an allyl(benzyl)-radical and allyl(benzyl)-Ti, which is protonated, regioselectively in case allylic derivatives.

An efficient binary collision approximation (BCA) ion implant code with good prediction capabilities for semiconductor materials (Si, GaAs, SiC) only one fitting parameter low implantation doses is presented. It includes specific interatomic potentials and recent improvements in physical models inelastic stopping. A periodic ab initio full bond electron density the target used. Damage accumulation supported using a modified Kinchin–Pease model [G. H. Kinchin R. S. Pease, Rep. Prog. Phys. 18,...

In order to simulate the diffusion kinetics during thermal treatments in SiGe heterostructures, a physically-based atomistic model including chemical and strain effects has been developed implemented into nonlattice kinetic monte carlo (KMC) framework. This is based on description of transport capacities native point defects (interstitials vacancies) with different charge states alloys whole composition range. Lattice atom diffusivities have formulated terms defect transport, taking account...

The catalytic hydrogenation of amides is an atom economical method to synthesize amines. Previously, it was serendipitously discovered that the combination a secondary amide co-catalyst with (iPrPNP)Fe(H)(CO) (iPrPNP = N[CH2CH2(PiPr2)]2 -), results in highly active base metal system for deaminative hydrogenation. Here, we use DFT develop improved Initially, computationally evaluated ability series co-catalysts accelerate turnover-limiting proton transfer during C-N bond cleavage and poison...

Atomistic simulations are used to study the effects of implant parameters on transient enhanced diffusion (TED). We analyze 10 keV Si implants in a wide range doses from 108 1014 ions/cm2, dose rates 1010 ions/cm2 s, and temperature room 1000 °C. Different regimes with different dependence TED these observed. For high doses, rates, low temperatures, Frenkel pairs accumulated during ion implantation, resulting damage is very dense. During postimplant annealing, recombination efficient, extra...

A comprehensive atomistic model for arsenic in silicon which includes charge effects and is consistent with first-principles calculations arsenic-vacancy cluster energies has been developed. Emphasis put reproducing the electrical deactivation annealed profiles preamorphized silicon. The simulations performed an kinetic Monte Carlo simulator suggest a predominant role of mobile interstitial experiments provide good understanding behavior during annealing.

Abstract Treatment of germacrone ( 1 ) with different electrophiles, and its epoxy derivatives germacrone‐4,5‐epoxide 2 ), germacrone‐1,10‐epoxide 3 isogermacrone‐4,5‐epoxide 4 Brönsted/Lewis acids Ti III , gives rise to a great structural diversity. Thus, by using maximum two steps, the production more than 40 compounds corresponding 14 skeletons is described. Computational calculations rationalizing divergence produced are also Finally, since some generated bioactive natural...

A new method for the optical cross-section measurement of deep levels in junctions is presented. It based on capacitance and conductance junction under illumination, as a function photon energy hν frequency measuring signal. This technique has been applied to capture cross section σon Au acceptor level corresponding emission electrons conduction band.

An accurate physically based Fermi-level modeling approach, amenable to be implemented in an atomistic process simulator, is reported. The kinetic Monte Carlo method used for point and extended defects, conjunction with a quasiatomistic, continuum approach treatment carrier densities. model implements charge reactions electric bias according the local Fermi level, pairing break-up between particles, clustering-related dopant deactivation, Fermi-level-dependent solubility. We derive...

In a recent article (ACS Catal. 2018, 8, 11119–11133), comprehensive catalytic mechanism is proposed to explain the effects of residual water on reactivity and regioselectivity tris(pentafluorophenyl)borane catalyst in ring-opening reaction 1,2-epoxyoctane by 2-propanol. Using it as representative example common trend followed also other groups, we show that heavily under-constrained (loose) kinetic modeling approach employed can lead several pitfalls propose an alternative, more stringent...