-While first versions of this simulation, just covering a limit depth region of the target in which selforganization is observed, have already been discussed in \cite{me1,me2}, only results of the new version, which is able to model the whole depth region affected by the irradiation process, will be presented.
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-A set of simulation parameters exists to properly describe the fluence dependent formation of the amorphous phase, as can be seen in Fig \ref{img:dose_cmp}.
-\ldots
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-By simulation it is possible to determine the carbon concentration in crystalline, amorphous and both volumes.
-Fig. \ref{img:carbon_distr} \ldots
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-Based on simulation runs a recipe is proposed to create broad distributions of lamellar structure.
-The starting point is a crystalline silcon target with a nearly constant carbon concentration of $10 \, at.\%$ starting from the surfcae downto $500 \, nm$, which can be achieved by multiple carbon implantation steps with energies between $180$ and $10 \, keV$ at a temperature $T=500 \, ^{\circ} \mathrm{C}$ to prevent amorphization \cite{sputter}.
-In a second step the target is irradiated with $2 \, MeV$ $C^+$ ions, which have a nearly constant energy loss and an essentially zero implantation profile in the affected depth region.
-The result is displayed in Fig. \ref{img:broad_lam}, showing already ordered structures after $s=100 \times 10^6$ steps corresponding to a fluence of $D=2.7 \times 10^{17} cm^{-2}$.
-The structure gets more defined with increasing fluence.
-According to recent studies \cite{photo} these structures are the starting point for materials showing high photoluminescence.
+First versions of this simulation just covered the limited depth region of the target in which selforganisation is observed [13,14].
+As can be seen in Fig. 3, the new version of the simulation code is able to model the whole depth region affected by the irradiation process and properly describes the fluence dependence of the amorphous phase formation.
+In Fig 3a) only isolated amorphous cells exist in the simulation and cross-section transmission electron microscopy (XTEM) shows dark contrasts, corresponding to highly distorted regions caused by defects.
+XTEM at higher magnification [9] shows the existence of amorphous inclusions which are $3 \, nm$ in size.
+For a fluence of $2.1 \times 10^{17} cm^{-2}$ a continuous amorphous layer is formed (Fig. 3b)).
+The simulation shows a broader continuous layer than observed experimentally.
+However dark contrasts below the continuous layer in the XTEM image of Fig. 3b) indicate a high concentration of defects and amorphous inclusions in this depth zone.
+The continuous amorphous layer together with the region showing the dark contrast has essentially the same thickness as the simulated continuous layer.
+For higher fluences (Fig. 3c) and d)) experimental and simulated data correspond to a high degree.
+The thickness of the continuous amorphous layer increases with increasing fluence.
+Next to the upper crystalline/amorphous interface, nanometric lamellar inclusions are formed which get more defined with increasing fluence, reflecting the progress of selforganisation.
+The difference in depth throughought all images is due to a deeper maximum of the used {\em SRIM} implantation profile compared to older, more accurate {\em TRIM} versions.
+
+By simulation it is possible to determine the carbon concentration in crystalline and amorphous volumes.
+This is shown in Fig. 4.
+Lamellae exist between $350$ and $400 \, nm$ and cause a fluctuation in the carbon concentration.
+This is due to the carbon diffusion, which is of great importance for the ordering process, as already pointed out in [13,14], and the complementarily arranged and alternating sequence of layers with high and low amount of amorphous regions.
+In addition, a saturation limit of carbon in c-$Si$ under the given implantation conditions can be identified between $8$ and $10 \, at. \%$, the maxima of carbon concentration in crystalline volumes.
+
+Based on above results a recipe is proposed to create thick layers with lamellar structure which might be favourable for applications.
+The starting point is a crystalline silcon target with a nearly constant carbon concentration of $10 \, at.\%$ in a $500 \, nm$ thick surface layer. This can possibly be achieved by multiple energy ($180$ to $10 \, keV$) carbon implantation at a temperature of $500 \, ^{\circ} \mathrm{C}$, preventing amorphisation [5].
+In a second step the target is irradiated at $150 \, ^{\circ} \mathrm{C}$ with $2 \, MeV$ $C^+$ ions, which have a nearly constant energy loss in the top $500 \, nm$ and do not significantly change the carbon concentration here.
+The result is displayed in Fig. 5.
+Already ordered structures appear after $100 \times 10^6$ steps corresponding to a fluence of $D=2.7 \times 10^{17} cm^{-2}$ and get more defined with increasing fluence.
+According to recent studies [15] these structures are expected to be the starting point for materials showing strong photoluminescence.