1 \documentclass[10pt]{scrartcl}
5 % resize to A0 (900 x 1100 mm) full poster size
9 % 2*sqrt(2) = 2.828 (for A0)
15 % special format, scaled by 2.82 -> A0
42 % ./poster_resize poster.ps S
45 % A3: 29.73 x 42.04 cm
53 \usepackage[latin1]{inputenc}
55 \usepackage{graphicx,psfrag,color,pstricks,pst-grad}
56 \graphicspath{{../img/}}
57 \usepackage{amsmath,amssymb}
61 \usepackage[german]{babel}
63 % numbers, lengths and boxes:
65 \newsavebox{\dummybox}
68 \newlength{\bgwidth}\newlength{\bgheight}
69 \setlength\bgheight{\hoehe} \addtolength\bgheight{-1mm}
70 \setlength\bgwidth{\breite} \addtolength\bgwidth{-1mm}
72 \newlength{\kastenwidth}
74 \setlength\paperheight{\hoehe}
75 \setlength\paperwidth{\breite}
76 \special{papersize=\breite,\hoehe}
84 \setlength{\oddsidemargin}{-2.44cm}
85 \addtolength{\topmargin}{-3mm}
87 \textheight\paperheight
90 \parskip1.5ex plus0.5ex minus 0.5ex
93 \definecolor{recoilcolor}{rgb}{1,0,0}
94 \definecolor{occolor}{rgb}{0,1,0}
95 \definecolor{pink}{rgb}{0,1,1}
97 \def\UberStil{\normalfont\sffamily\bfseries\large}
98 \def\UnterStil{\normalfont\sffamily\small}
99 \def\LabelStil{\normalfont\sffamily\tiny}
100 \def\LegStil{\normalfont\sffamily\tiny}
104 \definecolor{JG}{rgb}{0.1,0.9,0.3}
106 \newenvironment{kasten}{%
107 \begin{lrbox}{\dummybox}%
108 \begin{minipage}{0.96\linewidth}}%
111 \raisebox{-\depth}{\psshadowbox[framesep=1em]{\usebox{\dummybox}}}\\[0.5em]}
113 \newenvironment{spalte}{%
114 \setlength\kastenwidth{1.2\textwidth}
115 \divide\kastenwidth by \anzspalten
116 \begin{minipage}[t]{\kastenwidth}}
117 {\end{minipage}\hfill}
119 \renewcommand{\emph}[1]{{\color{red}\textbf{#1}}}
124 % the document begins ...
129 {\newrgbcolor{gradbegin}{0.1 0.1 0.1}%
130 \newrgbcolor{gradend}{1 1 1}%
131 \psframe[fillstyle=gradient,gradend=gradend,%
132 gradbegin=gradbegin,gradmidpoint=0.5](\bgwidth,-\bgheight)%
138 \psshadowbox{\makebox[0.95\textwidth]{%
140 \parbox[c]{0.1\linewidth}{\includegraphics[height=4.5cm]{uni-logo.eps}}
141 \parbox[c]{0.7\linewidth}{%
143 \textbf{\Huge{Monte Carlo simulation study of a
144 selforganization process\\
145 leading to ordered precipitate structures}
147 \textsc{\LARGE \underline{F. Zirkelbach}, M. H"aberlen,
148 J. K. N. Lindner, B. Stritzker
150 {\large Institut f"ur Physik, Universit"at Augsburg,
151 D-86135 Augsburg, Germany
155 \parbox[c]{0.1\linewidth}{%
156 \includegraphics[height=4.1cm]{Lehrstuhl-Logo.eps}
160 \hfill\mbox{}\\[1.cm]
164 % content, let's rock the columns
165 \begin{lrbox}{\spalten}
166 \parbox[t][\textheight]{1.3\textwidth}{%
173 % {\large{\color{blue}\underline{ABSTRACT}}}
176 % abstract ... skip it
177 %High-dose ion implantation into solids usually leads to a disordered distribution of defects or precipitates with variable sizes.
178 %However materials exist for which high-dose ion irradiation at certain conditions results in periodically arranged, self-organized, nanometric amorphous inclusions.
179 %This has been observed for a number of ion/target combinations \cite{ommen,specht,ishimaru} which all have in common a largely reduced density of host atoms of the amorphous phase compared to the crystalline host lattice.
180 %A simple model explaining the phenomenon is introduced and realized in a Monte Carlo simulation code, which focuses on high dose carbon implantation into silicon.
181 %The simulation is able to reproduce the depth distribution observed by TEM and RBS.
182 %While first versions of the simulation \cite{me1,me2} just covered a limited depth region of the target in which the selforganization is observed, the new version of this simulation code presented here is able to model the whole depth region affected by the irradiation process, as can be seen in chapter 4.
183 %Based on simulation results a recipe is proposed for producing broad distributions of lamellar, ordered structures which, according to recent studies \cite{wong}, are the starting point for materials with high photoluminescence.
189 \section*{1 \hspace{0.1cm} {\color{blue}Experimental observations}}
191 \subsection*{1.1 {\color{blue} Amorphous inclusions}}
193 \includegraphics[width=11cm]{k393abild1_e.eps}
195 Cross section TEM image:\\
196 $180 \, keV$ $C^+ \rightarrow Si$,
197 $T=150 \, ^{\circ} \mathrm{C}$,
198 Dose: $4.3 \times 10^{17} \, cm^{-2}$\\
199 black/white: crystalline/amorphous material\\
200 L: amorphous lamellae, S: spherical amorphous inclusions
202 \subsection*{1.2 {\color{blue} Carbon distribution}}
204 \includegraphics[width=11cm]{eftem.eps}
206 Brightfield TEM and respective EFTEM image:\\
207 $180 \, keV$ $C^+ \rightarrow Si$,
208 $T=200 \, ^{\circ} \mathrm{C}$,
209 Dose: $4.3 \times 10^{17} \, cm^{-2}$\\
210 yellow/blue: high/low concentrations of carbon
215 \section*{2 \hspace{0.1cm} {\color{blue}Model}}
218 \includegraphics[width=11cm]{modell_ng_e.eps}
221 \item supersaturation of $C$ in $c-Si$\\
222 $\rightarrow$ {\bf carbon induced} nucleation of spherical
224 \item high interfacial energy between $3C-SiC$ and $c-Si$\\
225 $\rightarrow$ {\bf amourphous} precipitates
226 \item $20 - 30\,\%$ lower silicon density of $a-SiC_x$ compared to $c-Si$\\
227 $\rightarrow$ {\bf lateral strain} (black arrows)
228 \item reduction of the carbon supersaturation in $c-Si$\\
229 $\rightarrow$ {\bf carbon diffusion} into amorphous volumina
231 \item lateral strain (vertical component relaxating)\\
232 $\rightarrow$ {\bf strain induced} lateral amorphization
238 \section*{3 \hspace{0.1cm} {\color{blue}Simulation}}
240 \subsection*{3.1 {\color{blue} Discretization of the target}}
242 \includegraphics[width=6cm]{gitter_e.eps}
245 \subsection*{3.2 {\color{blue} Simulation algorithm}}
247 \subsubsection*{3.2.1 Amorphization/Recrystallization}
249 \item random numbers according to the nuclear
250 energy loss to determine the volume hit
252 \item compute local probability for
255 p_{c \rightarrow a}(\vec{r}) = {\color{green} p_b} + {\color{blue} p_c c_C(\vec{r})} + {\color{red} \sum_{\textrm{amorphous neighbours}} \frac{p_s c_C(\vec{r'})}{(r-r')^2}}
257 and recrystallization:
259 p_{a \rightarrow c}(\vec r) = (1 - p_{c \rightarrow a}(\vec r)) \Big(1 - \frac{\sum_{direct \, neighbours} \delta (\vec{r'})}{6} \Big) \, \textrm{,}
262 \delta (\vec r) = \left\{
264 1 & \textrm{volume at position $\vec r$ amorphous} \\
265 0 & \textrm{otherwise} \\
269 \item loop for the mean amount of hits by the
272 Three contributions to the amorphization process controlled by:
274 \item {\color{green} $p_b$} normal 'ballistic' amorphization
275 \item {\color{blue} $p_c$} carbon induced amorphization
276 \item {\color{red} $p_s$} stress enhanced amorphization
279 \subsubsection*{3.2.2 Carbon incorporation}
281 \item random numbers according to the
282 implantation profile to determine the
284 \item increase the amount of carbon atoms in
287 \subsubsection*{3.2.3 Diffusion/Sputtering}
289 \item every $d_v$ steps transfer $d_r$ of the
290 carbon atoms of crystalline volumina to
291 an amorphous neighbour volume
292 \item do the sputter routine after $n$ steps
293 corresponding to $3 \, nm$ of substrat
300 \section*{4 \hspace{0.1cm} {\color{blue}Simulation results}}
302 \subsection*{4.1 {\color{blue} Comparison with experiments}}
304 \includegraphics[width=11cm]{dosis_entwicklung_ng_e_1-2.eps}
307 \includegraphics[width=11cm]{dosis_entwicklung_ng_e_2-2.eps}
310 \subsection*{4.1 {\color{blue} Carbon distribution}}
312 \includegraphics[width=11cm]{ac_cconc_ver2_e.eps}
320 \section*{5 \hspace{0.1cm} {\color{blue}Broad distribution of
324 \item $10 \, at.\%$ constant carbon plateau
325 by multiple implantation steps at
326 energies between $180$ and $10 \, keV$
329 \includegraphics[width=6cm]{multiple_impl_cp.eps}
332 \item foloowed by $2 \, MeV$ $C^+$ implantation
335 \includegraphics[width=10cm]{multiple_impl.eps}
342 \section*{6 \hspace{0.1cm} {\color{red} \underline{Conclusions}}}
359 \begin{thebibliography}{9}
360 \bibitem{ommen} A. H. van Ommen,
361 Nucl. Instr. and Meth. B 39 (1989) 194.
362 \bibitem{specht} E. D. Specht, D. A. Walko, S. J. Zinkle,
363 Nucl. Instr. and Meth. B 84 (2000) 390.
364 \bibitem{ishimaru} M. Ishimaru, R. M. Dickerson, K. E. Sickafus,
365 Nucl. Instr. and Meth. B 166-167 (2000) 390.
366 \bibitem{me1} F. Zirkelbach, M. H"aberlen, J. K. N. Lindner,
368 Comp. Mater. Sci. 33 (2005) 310.
369 \bibitem{me2} F. Zirkelbach, M. H"aberlen, J. K. N. Lindner,
371 Nucl. Instr. and Meth. B 242 (2006) 679.
372 \bibitem{wong} Dihu Chen, Z. M. Liao, L. Wang, H. Z. Wang, Fuli Zhao,
373 W. Y. Cheung, S. P. Wong,
374 Opt. Mater. 23 (2003) 65. Opt. Mater. 23 (2003) 65.
375 \end{thebibliography}
381 \resizebox*{0.98\textwidth}{!}{%
382 \usebox{\spalten}}\hfill\mbox{}\vfill