\begin{itemize}
\item First-principles investigation of defect combinations
and mobilities in Si
- \item Empirical potential MD simulations on SiC prcipitation in Si
+ \item Empirical potential MD simulations on SiC precipitation in Si
\end{itemize}
\vspace{0.2cm}
-\ifnum1=0
-
\begin{slide}
\headphd
\begin{slide}
+\headphd
+{\large\bf
+ IBS of epitaxial single crystalline 3C-SiC
+}
+
+\footnotesize
+
+\vspace{0.2cm}
+
+\begin{center}
+\begin{itemize}
+ \item \underline{Implantation step 1}\\[0.1cm]
+ Almost stoichiometric dose | \unit[180]{keV} | \degc{500}\\
+ $\Rightarrow$ Epitaxial {\color{blue}3C-SiC} layer \&
+ {\color{blue}precipitates}
+ \item \underline{Implantation step 2}\\[0.1cm]
+ Low remaining amount of dose | \unit[180]{keV} | \degc{250}\\
+ $\Rightarrow$
+ Destruction/Amorphization of precipitates at layer interface
+ \item \underline{Annealing}\\[0.1cm]
+ \unit[10]{h} at \degc{1250}\\
+ $\Rightarrow$ Homogeneous 3C-SiC layer with sharp interfaces
+\end{itemize}
+\end{center}
+
+\begin{minipage}{6.9cm}
+\includegraphics[width=7cm]{ibs_3c-sic.eps}\\[-0.4cm]
+\begin{center}
+{\tiny
+ XTEM: single crystalline 3C-SiC in Si\hkl(1 0 0)
+}
+\end{center}
+\end{minipage}
+\begin{minipage}{5cm}
+\begin{center}
+\begin{pspicture}(0,0)(0,0)
+\rnode{box}{
+\psframebox[fillstyle=solid,fillcolor=white,linecolor=blue,linestyle=solid]{
+\begin{minipage}{3.3cm}
+ \begin{center}
+ {\color{blue}
+ 3C-SiC precipitation\\
+ not yet fully understood
+ }
+ \end{center}
+% \vspace*{0.1cm}
+% \renewcommand\labelitemi{$\Rightarrow$}
+% Details of the SiC precipitation
+% \begin{itemize}
+% \item significant technological progress\\
+% in SiC thin film formation
+% \item perspectives for processes relying\\
+% upon prevention of SiC precipitation
+% \end{itemize}
+\end{minipage}
+}}
+\rput(-5.3,5.5){\pnode{h0}}
+\rput(-1.95,5.5){\pnode{h1}}
+\ncline[linecolor=blue]{-}{h0}{h1}
+\ncline[linecolor=blue]{->}{h1}{box}
+\end{pspicture}
+\end{center}
+\end{minipage}
+
+\end{slide}
+
+\begin{slide}
+
\footnotesize
\headphd
\end{slide}
+\begin{slide}
+
+\headphd
+{\large\bf\boldmath
+ C interstitial migration --- ab initio
+}
+
+\scriptsize
+
+\vspace{0.3cm}
+
+\begin{minipage}{6.8cm}
+\framebox{\hkl[0 0 -1] $\rightarrow$ \hkl[0 0 1]}\\
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/100_2333.eps}
+\end{minipage}
+\begin{minipage}{0.2cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/bc_2333.eps}
+\end{minipage}
+\begin{minipage}{0.2cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/100_next_2333.eps}
+\end{minipage}\\[0.1cm]
+Symmetry:\\
+$\Rightarrow$ Sufficient to consider \hkl[00-1] to BC transition\\
+$\Rightarrow$ Migration barrier to reach BC | $\Delta E=\unit[1.2]{eV}$
+\end{minipage}
+\begin{minipage}{5.4cm}
+\includegraphics[width=6.0cm]{im_00-1_nosym_sp_fullct_thesis_vasp_s.ps}
+%\end{minipage}\\[0.2cm]
+\end{minipage}\\[0.4cm]
+%\hrule
+%
+\begin{minipage}{6.8cm}
+\framebox{\hkl[0 0 -1] $\rightarrow$ \hkl[0 -1 0]}\\
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/100_2333.eps}
+\end{minipage}
+\begin{minipage}{0.2cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/00-1-0-10_2333.eps}
+\end{minipage}
+\begin{minipage}{0.2cm}
+$\rightarrow$
+\end{minipage}
+\begin{minipage}{2.0cm}
+\includegraphics[width=2.0cm]{c_pd_vasp/0-10_2333.eps}
+\end{minipage}\\[0.1cm]
+$\Delta E=\unit[0.9]{eV}$ | Experimental values: \unit[0.70--0.87]{eV}\\
+$\Rightarrow$ {\color{red}Migration mechanism identified!}\\
+Note: Change in orientation
+\end{minipage}
+\begin{minipage}{5.4cm}
+\includegraphics[width=6.0cm]{00-1_0-10_vasp_s.ps}
+\end{minipage}\\[0.1cm]
+%
+%\begin{center}
+%Reorientation pathway composed of two consecutive processes of the above type
+%\end{center}
+
+\end{slide}
+
+\begin{slide}
+
+\headphd
+{\large\bf\boldmath
+ C interstitial migration --- analytical potential
+}
+\scriptsize
+
+\vspace{0.3cm}
+
+\begin{minipage}[t]{6.0cm}
+{\bf\boldmath BC to \hkl[0 0 -1] transition}\\[0.2cm]
+\includegraphics[width=6.0cm]{bc_00-1_albe_s.ps}\\
+\begin{itemize}
+ \item Lowermost migration barrier
+ \item $\Delta E \approx \unit[2.2]{eV}$
+ \item 2.4 times higher than ab initio result
+ \item Different pathway
+\end{itemize}
+\end{minipage}
+\begin{minipage}[t]{0.2cm}
+\hfill
+\end{minipage}
+\begin{minipage}[t]{6.0cm}
+{\bf\boldmath Transition involving a \hkl<1 1 0> configuration}
+\vspace{0.1cm}
+\begin{itemize}
+ \item Bond-centered configuration unstable\\
+ $\rightarrow$ \ci{} \hkl<1 1 0> dumbbell
+ \item Minimum of the \hkl[0 0 -1] to \hkl[0 -1 0] transition\\
+ $\rightarrow$ \ci{} \hkl<1 1 0> DB
+\end{itemize}
+\vspace{0.1cm}
+\includegraphics[width=6.0cm]{00-1_110_0-10_mig_albe.ps}
+\begin{itemize}
+ \item $\Delta E \approx \unit[2.2]{eV} \text{ \& } \unit[0.9]{eV}$
+ \item 2.4 -- 3.4 times higher than ab initio result
+ \item After all: Change of the DB orientation
+\end{itemize}
+\end{minipage}
+
+\vspace{0.5cm}
+\begin{center}
+{\color{red}\bf Drastically overestimated diffusion barrier}
+\end{center}
+
+\begin{pspicture}(0,0)(0,0)
+\psline[linewidth=0.05cm,linecolor=gray](6.1,1.0)(6.1,9.3)
+\end{pspicture}
+
+\end{slide}
+
+\begin{slide}
+
+\headphd
+{\large\bf\boldmath
+ Silicon carbide precipitation simulations at \degc{450} as in IBS
+}
+
+\small
+
+\begin{minipage}{6.3cm}
+\hspace*{-0.4cm}\includegraphics[width=6.5cm]{sic_prec_450_si-c.ps}\\
+\hspace*{-0.4cm}\includegraphics[width=6.5cm]{sic_prec_450_si-si_c-c.ps}
+\hfill
+\end{minipage}
+\begin{minipage}{6.1cm}
+\scriptsize
+\underline{Low C concentration --- {\color{red}$V_1$}}\\[0.1cm]
+\ci{} \hkl<1 0 0> dumbbell dominated structure
+\begin{itemize}
+ \item Si-C bumbs around \unit[0.19]{nm}
+ \item C-C peak at \unit[0.31]{nm} (expected in 3C-SiC):\\
+ concatenated differently oriented \ci{} DBs
+ \item Si-Si NN distance stretched to \unit[0.3]{nm}
+\end{itemize}
+\begin{pspicture}(0,0)(6.0,1.0)
+\rput(3.2,0.5){\psframebox[linewidth=0.03cm,linecolor=blue]{
+\begin{minipage}{6cm}
+\centering
+Formation of \ci{} dumbbells\\
+C atoms separated as expected in 3C-SiC
+\end{minipage}
+}}
+\end{pspicture}\\[0.1cm]
+\underline{High C concentration --- {\color{green}$V_2$}/{\color{blue}$V_3$}}
+\begin{itemize}
+\item High amount of strongly bound C-C bonds
+\item Increased defect \& damage density\\
+ $\rightarrow$ Arrangements hard to categorize and trace
+\item Only short range order observable
+\end{itemize}
+\begin{pspicture}(0,0)(6.0,0.8)
+\rput(3.2,0.5){\psframebox[linewidth=0.03cm,linecolor=blue]{
+\begin{minipage}{6cm}
+\centering
+Amorphous SiC-like phase
+\end{minipage}
+}}
+\end{pspicture}\\[0.3cm]
+\begin{pspicture}(0,0)(6.0,2.0)
+\rput(3.2,1.0){\psframebox[linewidth=0.05cm,linecolor=black]{
+\begin{minipage}{6cm}
+\vspace{0.1cm}
+\centering
+{\bf\color{red}Formation of 3C-SiC fails to appear}\\[0.3cm]
+\begin{minipage}{0.8cm}
+{\bf\boldmath $V_1$:}
+\end{minipage}
+\begin{minipage}{5.1cm}
+Formation of \ci{} indeed occurs\\
+Agllomeration not observed
+\end{minipage}\\[0.3cm]
+\begin{minipage}{0.8cm}
+{\bf\boldmath $V_{2,3}$:}
+\end{minipage}
+\begin{minipage}{5.1cm}
+Amorphous SiC-like structure\\
+(not expected at \degc{450})\\[0.05cm]
+No rearrangement/transition into 3C-SiC
+\end{minipage}\\[0.1cm]
+\end{minipage}
+}}
+\end{pspicture}
+\end{minipage}
+
+\end{slide}
+
+\begin{slide}
+
+\headphd
+{\large\bf\boldmath
+ Increased temperature simulations --- $V_1$
+}
+
+\small
+
+\begin{minipage}{6.2cm}
+\hspace*{-0.4cm}\includegraphics[width=6.5cm]{tot_pc_thesis.ps}
+\hfill
+\end{minipage}
+\begin{minipage}{6.2cm}
+\includegraphics[width=6.5cm]{tot_pc3_thesis.ps}
+\end{minipage}
+
+\begin{minipage}{6.2cm}
+\hspace*{-0.4cm}\includegraphics[width=6.5cm]{tot_pc2_thesis.ps}
+\hfill
+\end{minipage}
+\begin{minipage}{6.3cm}
+\scriptsize
+ \underline{Si-C bonds:}
+ \begin{itemize}
+ \item Vanishing cut-off artifact (above $1650\,^{\circ}\mathrm{C}$)
+ \item Structural change: \ci{} \hkl<1 0 0> DB $\rightarrow$
+ {\color{blue}\cs{}}
+ \end{itemize}
+ \underline{Si-Si bonds:}
+ {\color{blue}Si-C$_{\text{sub}}$-Si} along \hkl<1 1 0>
+ ($\rightarrow$ 0.325 nm)\\[0.1cm]
+ \underline{C-C bonds:}
+ \begin{itemize}
+ \item C-C next neighbour pairs reduced (mandatory)
+ \item Peak at 0.3 nm slightly shifted\\[0.05cm]
+ $\searrow$ \ci{} combinations (dashed arrows)\\
+ $\nearrow$ \ci{} \hkl<1 0 0> \& {\color{blue}\cs{} combinations} (|)\\
+ $\nearrow$ \ci{} pure \cs{} combinations ($\downarrow$)\\[0.05cm]
+ Range [|-$\downarrow$]: {\color{blue}\cs{} \& \cs{} with nearby \si}
+ \end{itemize}
+\end{minipage}
+
+\end{slide}
+
\begin{slide}
{\large\bf
\end{slide}
-
-
-\begin{slide}
-
- {\large\bf
- Valuation of a practicable temperature limit
- }
-
- \small
-
-\vspace{0.1cm}
-
-\begin{center}
-\framebox{
-{\color{blue}
-Recrystallization is a hard task!
-$\Rightarrow$ Avoid melting!
-}
-}
-\end{center}
-
-\vspace{0.1cm}
-
-\footnotesize
-
-\begin{minipage}{6.4cm}
-\includegraphics[width=6.4cm]{fe_and_t.ps}
-\end{minipage}
-\begin{minipage}{5.7cm}
-\underline{Melting does not occur instantly after}\\
-\underline{exceeding the melting point $T_{\text{m}}=2450\text{ K}$}
-\begin{itemize}
-\item required transition enthalpy
-\item hysterisis behaviour
-\end{itemize}
-\underline{Heating up c-Si by 1 K/ps}
-\begin{itemize}
-\item transition occurs at $\approx$ 3125 K
-\item $\Delta E=0.58\text{ eV/atom}=55.7\text{ kJ/mole}$\\
- (literature: 50.2 kJ/mole)
-\end{itemize}
-\end{minipage}
-
-\vspace{0.1cm}
-
-\framebox{
-\begin{minipage}{4cm}
-Initially chosen temperatures:\\
-$1.0 - 1.2 \cdot T_{\text{m}}$
-\end{minipage}
-}
-\begin{minipage}{2cm}
-\begin{center}
-$\Longrightarrow$
-\end{center}
-\end{minipage}
-\framebox{
-\begin{minipage}{5cm}
-Introduced C (defects)\\
-$\rightarrow$ reduction of transition point\\
-$\rightarrow$ melting already at $T_{\text{m}}$
-\end{minipage}
-}
-
-\vspace{0.4cm}
-
-\begin{center}
-\framebox{
-{\color{blue}
-Maximum temperature used: $0.95\cdot T_{\text{m}}$
-}
-}
-\end{center}
-
-\end{slide}
-
\begin{slide}
{\large\bf
\end{slide}
-\fi
-
\end{document}
projects / lectures / latex.git / blobdiff