]> hackdaworld.org Git - lectures/latex.git/commitdiff
iadded version 2 (mods to obsolete ver1)
authorhackbard <hackbard>
Mon, 14 Aug 2006 14:40:16 +0000 (14:40 +0000)
committerhackbard <hackbard>
Mon, 14 Aug 2006 14:40:16 +0000 (14:40 +0000)
nlsop/poster/nlsop_ibmm2006.tex
nlsop/poster/nlsop_ibmm2006_ver2.tex [new file with mode: 0644]

index 1188e13d5365c5c2420a76380df8e40c85b2f89f..098893771024e247f4e48076db03a6011bfcea13 100644 (file)
        }
        %\hfill
 }}
-\hfill\mbox{}\\[0.1cm]
+\hfill\mbox{}\\[0cm]
 
 %\vspace*{1.3cm}
 
       $\rightarrow$ {\bf amourphous} precipitates
 \item $20 - 30\,\%$ lower silicon density of $a-SiC_x$ compared to $c-Si$\\
       $\rightarrow$ {\bf lateral strain} (black arrows)
+\item implantation range near surface\\
+      $\rightarrow$ {\bf ralaxation} of {\bf vertical strain component}
 \item reduction of the carbon supersaturation in $c-Si$\\
       $\rightarrow$ {\bf carbon diffusion} into amorphous volumina
       (white arrows)
-\item lateral strain (vertical component relaxating)\\
+\item remaining lateral strain\\
       $\rightarrow$ {\bf strain induced} lateral amorphization
                        \end{itemize}
        \end{kasten}
 
                \subsubsection*{3.2.1 Amorphization/Recrystallization}
                        \begin{itemize}
-                               \item random numbers according to the nuclear
-                                     energy loss to determine the volume hit
-                                     by an impinging ion
+                               \item random numbers distributed according to 
+                                     the nuclear energy loss to determine the
+                                     volume hit by an impinging ion
                                \item compute local probability for
                                      amorphization:\\
 \[
@@ -289,8 +291,8 @@ Three contributions to the amorphization process controlled by:
 
                \subsubsection*{3.2.2 Carbon incorporation}
                        \begin{itemize}
-                               \item random numbers according to the
-                                     implantation profile to determine the
+                               \item random numbers distributed according to
+                                     the implantation profile to determine the
                                      incorporation volume
                                \item increase the amount of carbon atoms in
                                      that volume
@@ -353,9 +355,10 @@ Three contributions to the amorphization process controlled by:
                        \makebox[11cm]{%
                                \parbox[c]{5cm}{%
                        \begin{itemize}
-                               \item multiple implantation \\ steps
+                               \item multiple implantation\\
+                                     steps
                                \item energies: $180$ - $10 \, keV$
-                               \item higher temeprature\\
+                               \item temeprature: $500 ^{\circ} \mathrm{C}$\\
                                      $\rightarrow$ prevent amorphization
                        \end{itemize}
                        $\Rightarrow$ nearly constant carbon distribution
@@ -370,14 +373,17 @@ Three contributions to the amorphization process controlled by:
                        \begin{center}              
                        \includegraphics[width=10cm]{multiple_impl_e.eps}
                        \end{center}
+                       Starting point for materials with high photoluminescence.\\
+                       Dihu Chen et al. Opt. Mater. 23 (2003) 65.
 
        \end{kasten}
        \begin{kasten}
-               \section*{5 \hspace{0.1cm} {\color{red} Conclusions}}
+               \section*{5 \hspace{0.1cm} {\color{red} Conclusion}}
                        \begin{itemize}
                \item selforganized nanometric precipitates by ion irradiation
                \item model describing the seoforganization process
-               \item precipitate structures traceable by simulation
+               \item set of parameters reproducing the experimental observations
+               \item precipitation process traceable by simulation
                \item detailed structural/compositional information
                \item recipe for broad distributions of lamellar structure
                        \end{itemize}
diff --git a/nlsop/poster/nlsop_ibmm2006_ver2.tex b/nlsop/poster/nlsop_ibmm2006_ver2.tex
new file mode 100644 (file)
index 0000000..e1ed083
--- /dev/null
@@ -0,0 +1,317 @@
+\documentclass[portrait,a0b,final]{a0poster}
+\usepackage{epsf,psfig,pstricks,multicol,pst-grad,color}
+\usepackage{graphicx,amsmath,amssymb}
+\graphicspath{{../img/}}
+\usepackage[german]{babel}
+
+\begin{document}
+
+% Fliessenden Hintergrund von RGB-Farbe 1. .98 .98 nach 1. .85 .85
+% und wieder nach  1. .98 .98 (1. .85 .85 wird nach 0.1=10% des Hinter-
+% grunds angenommen)
+% Achtung Werte unter .8 verbrauchen zu viel Tinte!!!
+
+%\background{.95 .95 1.}{.78 .78 1.}{0.05}
+\background{.50 .50 .50}{.85 .85 .85}{0.5}
+%\newrgbcolor{blue1}{.9 .9 1.}
+
+% Groesse der einzelnen Spalten als Anteil der Gesamt-Textbreite
+\renewcommand{\columnfrac}{.31}
+
+% header
+\vspace{-1cm}
+\begin{header}
+  \begin{minipage} {.13\textwidth}
+       \includegraphics[height=11cm]{uni-logo.eps}
+  \end{minipage} \hfill
+  \begin{minipage}   {.73\textwidth}
+     \centerline{{\Huge \bfseries Monte Carlo simulation study of a selforganisation}}
+     \centerline{{\Huge \bfseries process leading to ordered precipitate structures}}
+     \vspace*{1cm}
+     \centerline{\huge\textsc {\underline{F.~Zirkelbach}}, M.~H"aberlen,
+                               J.~K.~N.~Lindner, B.~Stritzker}
+     \vspace*{1cm}
+     \centerline{\Large Institut f"ur Physik, Universit"at Augsburg,
+                        D-86135 Augsburg, Germany}
+  \end{minipage} \hfill
+  \begin{minipage} {.13\textwidth}
+      \includegraphics[height=10cm]{Lehrstuhl-Logo.eps}
+  \end{minipage} \hfill
+\end{header}
+
+\begin{poster}
+
+\vspace{-1cm}
+\begin{pcolumn}
+  \begin{pbox}
+    \section*{Motivation}
+       {\bf
+       Experimentally observerd seflorganisation process at high-dose carbon
+       implantations under certain implantation conditions.}
+       \begin{itemize}
+               \item Spherical and lamellar amorphous inclusions at the upper
+                     a/c interface
+               \begin{center}
+                       \includegraphics[width=20cm]{k393abild1_e.eps}
+               \end{center}
+               Cross section TEM image:\\
+               $180 \, keV$ $C^+ \rightarrow Si$,
+               $T=150 \, ^{\circ} \mathrm{C}$,
+               Dose: $4.3 \times 10^{17} \, cm^{-2}$\\
+               black/white: crystalline/amorphous material\\
+               L: amorphous lamellae, S: spherical amorphous inclusions
+               \item Carbon accumulation in amorphous volumes
+               \begin{center}
+                       \includegraphics[width=20cm]{eftem.eps}
+               \end{center}
+               Brightfield TEM and respective EFTEM image:\\
+               $180 \, keV$ $C^+ \rightarrow Si$,
+               $T=200 \, ^{\circ} \mathrm{C}$,
+               Dose: $4.3 \times 10^{17} \, cm^{-2}$\\
+               yellow/blue: high/low concentrations of carbon
+       \end{itemize}
+       {\bf
+       Observed for a number of ion/target combinations for which the
+       material undergoes drastic density change upon amorphisation.}\\
+       {\scriptsize
+       A. H. van Ommen, Nucl. Instr. and Meth. B 39 (1989) 194.\\
+       E. D. Specht et al., Nucl. Instr. and Meth. B 84 (1994) 323.\\
+       M. Ishimaru et al., Nucl. Instr. and Meth. B 166-167 (2000) 390.}
+  \end{pbox}
+  \vspace{-1cm}
+  \begin{pbox}
+    \section*{Model}
+       {\bf
+       Model schematically displaying the formation of ordered lamellae
+       with increasing dose.}
+       \vspace{1cm}
+       \begin{center}
+               \includegraphics[width=20cm]{modell_ng_e.eps}
+       \end{center}
+       \begin{itemize}
+\item supersaturation of $C$ in $c-Si$\\
+      $\rightarrow$ {\bf carbon induced} nucleation of spherical
+      $SiC_x$-precipitates
+\item high interfacial energy between $3C-SiC$ and $c-Si$\\
+      $\rightarrow$ {\bf amourphous} precipitates
+\item $20 - 30\,\%$ lower silicon density of $a-SiC_x$ compared to $c-Si$\\
+      $\rightarrow$ {\bf lateral strain} (black arrows)
+\item implantation range near surface\\
+      $\rightarrow$ {\bf ralaxation} of {\bf vertical strain component}
+\item reduction of the carbon supersaturation in $c-Si$\\
+      $\rightarrow$ {\bf carbon diffusion} into amorphous volumina
+      (white arrows)
+\item remaining lateral strain\\
+      $\rightarrow$ {\bf strain induced} lateral amorphisation
+       \end{itemize}
+  \end{pbox}
+  \vspace{-1cm}
+  \begin{pbox}
+    \section*{Simulation}
+       \begin{minipage}[t]{0.5\textwidth}
+               {\bf Discretisation of the target}
+               \begin{center}
+                       \includegraphics[width=12cm]{gitter_e.eps}
+               \end{center}
+               \vspace{2cm}
+               \begin{itemize}
+                       \item divided into cells with a cube length of $3 \, nm$
+                       \item periodic boundary conditions in $x$,$y$-direction
+               \end{itemize}
+       \end{minipage}
+       \begin{minipage}[t]{0.5\textwidth}
+               {\bf TRIM collsion statstics}
+               \begin{center}
+                       \includegraphics[width=12cm]{trim_coll_e.eps}
+               \end{center}
+               \begin{itemize}
+                       \item[] $\Rightarrow$ identical depth profiles for
+                                number of
+                               collisions per depth and nuclear stopping power
+                       \item[] $\Rightarrow$ mean constant energy loss per
+                                collision
+               \end{itemize}
+       \end{minipage}
+  \end{pbox}
+
+
+\end{pcolumn}
+\begin{pcolumn}
+
+  \begin{pbox}
+    \section*{Simulation algorithm}
+    {\bf
+    The simulation algorithm consists of the following three parts looped 
+    $s$ times corresponding to a dose $D=s/(64\times64\times(3 \, nm)^2)$:}
+       \subsection*{1. Amorphisation/Recrystallisation}
+       \begin{itemize}
+               \item random numbers distributed according to
+                     the nuclear energy loss to determine the
+                     volume in which a collision occurs
+               \item compute local probability for amorphisation:\\
+                     %\vspace{0.1cm}
+
+                     \centerline{\fcolorbox[rgb]{0.,0.,0.}{1.,1.,.8}{
+                     \begin{minipage}{20cm}
+\[
+ p_{c \rightarrow a}(\vec{r}) = {\color{green} p_b} + {\color{blue} p_c c_C(\vec{r})} + {\color{red} \sum_{\textrm{amorphous neighbours}} \frac{p_s c_C(\vec{r'})}{(r-r')^2}}
+\]
+                     \end{minipage}
+                     }}
+                     \vspace{1cm}
+                     and recrystallisation:\\
+                     %\vspace{0.1cm}
+
+                     \centerline{\fcolorbox[rgb]{0.,0.,0.}{1.,1.,.8}{
+                     \begin{minipage}{20cm}
+\[
+p_{a \rightarrow c}(\vec r) = (1 - p_{c \rightarrow a}(\vec r)) \Big(1 - \frac{\sum_{direct \, neighbours} \delta (\vec{r'})}{6} \Big) \, \textrm{,}
+\]
+\[
+\delta (\vec r) = \left\{
+\begin{array}{ll}
+       1 & \textrm{if volume at position $\vec r$ is amorphous} \\
+       0 & \textrm{otherwise} \\
+\end{array}
+\right.
+\]
+                     \end{minipage}
+                     }}
+                     \vspace{1cm}
+               \item loop for the mean amount of hits by the ion
+       \end{itemize}
+       Three contributions to the amorphisation process controlled by:
+       \begin{itemize}
+               \item {\color{green} $p_b$} normal 'ballistic' amorphisation
+               \item {\color{blue} $p_c$} carbon induced amorphisation
+               \item {\color{red} $p_s$} stress enhanced amorphisation
+       \end{itemize}
+       \subsection*{2. Carbon incorporation}
+               \begin{itemize}
+                       \item random numbers distributed according to
+                             the implantation profile to determine the
+                             incorporation volume
+                       \item increase the amount of carbon atoms in
+                             that volume
+               \end{itemize}
+       \subsection*{3. Diffusion/Sputtering}
+               \begin{itemize}
+                       \item every $d_v$ steps transfer $d_r$ of the
+                             carbon atoms of crystalline volumina to
+                             an amorphous neighbour volume
+                       \item do the sputter routine after $n$ steps
+                             corresponding to $3 \, nm$ of substrat
+                             removal
+               \end{itemize}
+               {\bf
+               Simulation parameters $d_v$, $d_r$ and $n$ control the
+               diffusion and sputtering process.}
+  \end{pbox}
+  \vspace{-1cm}
+  \begin{pbox}
+       \section*{Comparison of experiment and simulation}
+        \begin{center}
+               \includegraphics[width=25cm]{dosis_entwicklung_ng_e_1-2.eps}
+       \end{center}
+       \begin{center}
+               \includegraphics[width=25cm]{dosis_entwicklung_ng_e_2-2.eps}
+       \end{center}
+       Simulation parameters:\\
+       $p_b=0.01$, $p_c=0.001$, $p_s=0.0001$, $d_r=0.05$, $d_v=1 \times 10^6$.
+       \\[0.7cm]{\bf Conclusion:}
+       \begin{itemize}
+               \item Essentially conforming formation and growth of the
+                     continuous amorphous layer
+               \item Lamellar precipitates and their evolution at the upper
+                     a/c interface with increasing dose is reproduced
+       \end{itemize}
+       {\bf\color{red} Simulation is able to model the whole
+                       depth region affected by the 
+                       irradiation process}
+  \end{pbox}
+\end{pcolumn}
+\begin{pcolumn}
+
+  \begin{pbox}
+       \section*{Structural/compositional information}
+       \begin{minipage}[t]{0.57\textwidth}
+               \includegraphics[height=15cm=]{ac_cconc_ver2_e.eps}
+               \begin{itemize}
+                       \item Fluctuation of the carbon concentration in the
+                             region of the lamellae
+                       \item Saturation limit of carbon in c-$Si$ under given
+                             implantation conditions between $8$ and
+                             $10 \, at. \%$
+               \end{itemize}
+       \end{minipage}
+       \begin{minipage}[t]{0.43\textwidth}
+               \includegraphics[height=15cm]{97_98_ng_e.eps}
+               \begin{itemize}
+                       \item Complementarily arranged and alternating sequence
+                             of layers with high and low amount of amorphous
+                             regions
+                       \item Carbon accumulation in the amorphous phase
+               \end{itemize}
+       \end{minipage}
+  \end{pbox}
+  \vspace{-1cm}
+  \begin{pbox}
+       \section*{Recipe:\\
+                 Thick films of ordered lamellar structure}
+       {\bf Prerequisites:}\\
+               Crystalline silicon target with a nearly constant carbon
+               concentration at $10 \, at. \%$ in a $500 \, nm$ thick
+               surface layer   
+       \begin{center}
+               \includegraphics[width=18cm]{multiple_impl_cp_e.eps}
+       \end{center}
+       {\bf Creation:}
+       \begin{itemize}
+               \item multiple energy ($180$-$10 \, keV$) $C^+$ $\rightarrow$
+                     $Si$ implantation
+               \item $T=500 \, ^{\circ} \mathrm{C}$, to prevent amorphisation
+       \end{itemize}
+       {\bf Stiring up:}\\
+       2nd $2 \, MeV$ $C^+$ $\rightarrow$ $Si$ implantation step at
+       $150 \, ^{\circ} \mathrm{C}$
+       \begin{itemize}
+               \item This does not significantly change the carbon
+                     concentration in the top $500 \, nm$
+               \item Nearly constant energy loss in the affected depth region
+       \end{itemize}
+       {\bf Result:}
+       \begin{center}
+               \includegraphics[width=25cm]{multiple_impl_e.eps}
+       \end{center}
+       \begin{itemize}
+               \item Already ordered structures after $100 \times 10^6$ steps
+                     corresponding to a dose of $D=2.7 \times 10^{17} cm^{-2}$
+               \item More defined structures with increasing dose
+       \end{itemize}
+       {\bf\color{blue} Starting point for materials showing strong\\
+                        photoluminescence}\\
+       {\scriptsize Dihu Chen et al. Opt. Mater. 23 (2003) 65.}
+  \end{pbox}
+  \vspace{-1cm}
+  \begin{pbox}
+       \section*{Conclusions}
+               \begin{itemize}
+                       \item Observation of self-organised nanometric
+                             precipitates by ion irradiation
+                       \item Model proposed describing the seoforganisation
+                             process
+                       \item Model implemented to a Monte Carlo simulation code
+                       \item Simulation is able to reproduce experimenal
+                             observations
+                       \item Precipitation process gets traceable by simulation
+                       \item Detailed structural/compositional information
+                             available by simulation
+                       \item Recipe proposed for the formation of broad
+                             distributions of lamellar structure
+               \end{itemize}
+  \end{pbox}
+
+\end{pcolumn}
+\end{poster}
+\end{document}
+