% layout check
%\layout
+\ifnum1=0
\begin{slide}
\center
{\Huge
E\\
}
\end{slide}
+\fi
% topic
\vspace{16pt}
- {\LARGE\bf
- Atomistic simulation study\\[0.2cm]
- on silicon carbide precipitation\\[0.2cm]
- in silicon
+ {\Large\bf
+ \hrule
+ \vspace{5pt}
+ Atomistic simulation study on silicon carbide\\[0.2cm]
+ precipitation in silicon\\
+ \vspace{10pt}
+ \hrule
}
- \vspace{48pt}
+ \vspace{60pt}
\textsc{Frank Zirkelbach}
- \vspace{48pt}
+ \vspace{60pt}
Defense of doctor's thesis
\vspace{08pt}
- Augsburg, 10. Jan. 2012
+ Augsburg, 10.01.2012
\end{center}
\end{slide}
% no vertical centering
\centerslidesfalse
+% skip for preparation
+%\ifnum1=0
+
% intro
% motivation / properties / applications of silicon carbide
\begin{slide}
+\headphd
{\large\bf
- Polytypes of SiC\\[0.4cm]
+ Polytypes of SiC\\[0.6cm]
}
+\vspace{0.6cm}
+
\includegraphics[width=3.8cm]{cubic_hex.eps}\\
\begin{minipage}{1.9cm}
{\tiny cubic (twist)}
\end{tabular}
\begin{pspicture}(0,0)(0,0)
-\psellipse[linecolor=green](5.7,2.10)(0.4,0.5)
+\psellipse[linecolor=green](5.7,2.05)(0.4,0.50)
\end{pspicture}
\begin{pspicture}(0,0)(0,0)
-\psellipse[linecolor=green](5.6,0.92)(0.4,0.2)
+\psellipse[linecolor=green](5.6,0.89)(0.4,0.20)
\end{pspicture}
\begin{pspicture}(0,0)(0,0)
-\psellipse[linecolor=red](10.45,0.45)(0.4,0.2)
+\psellipse[linecolor=red](10.45,0.42)(0.4,0.20)
\end{pspicture}
\end{slide}
\includegraphics[width=2.0cm]{cree.eps}
\end{picture}
-\vspace{-0.2cm}
+\vspace{-0.5cm}
+
+\begin{center}
+\color{red}
+\framebox{
+{\footnotesize\color{black}
+ Mismatch in \underline{thermal expansion coeefficient}
+ and \underline{lattice parameter} w.r.t. substrate
+}
+}
+\end{center}
+
+\vspace{0.1cm}
-Alternative approach:
+{\bf Alternative approach}\\
Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0)
-\vspace{0.2cm}
+\vspace{0.1cm}
\scriptsize
\end{minipage}
}
\begin{minipage}{5.5cm}
- \includegraphics[width=5.8cm]{ibs_3c-sic.eps}\\[-0.2cm]
- \begin{center}
- {\tiny
- XTEM: single crystalline 3C-SiC in Si\hkl(1 0 0)
- }
- \end{center}
-\end{minipage}
-
-\end{slide}
-
-% contents
-
-\begin{slide}
-
-\headphd
-{\large\bf
- Outline
+\begin{center}
+{\footnotesize
+No surface bending effects\\
+High areal homogenity\\[0.1cm]
+$\Downarrow$\\[0.1cm]
+Synthesis of large area SiC films possible
}
-
- \begin{itemize}
- \item Supposed precipitation mechanism of SiC in Si
- \item Utilized simulation techniques
- \begin{itemize}
- \item Molecular dynamics (MD) simulations
- \item Density functional theory (DFT) calculations
- \end{itemize}
- \item C and Si self-interstitial point defects in silicon
- \item Silicon carbide precipitation simulations
- \item Summary / Conclusion / Outlook
- \end{itemize}
+\end{center}
+\end{minipage}
\end{slide}
\headphd
{\large\bf
- Formation of epitaxial single crystalline 3C-SiC
+ IBS of epitaxial single crystalline 3C-SiC
}
\footnotesize
\end{itemize}
\end{center}
-\begin{minipage}{7cm}
-\includegraphics[width=7cm]{ibs_3c-sic.eps}
+\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{pspicture}(0,0)(0,0)
\end{itemize}
\end{minipage}
}}
-\rput(-6.8,5.4){\pnode{h0}}
-\rput(-3.0,5.4){\pnode{h1}}
+\rput(-6.8,5.5){\pnode{h0}}
+\rput(-3.0,5.5){\pnode{h1}}
\ncline[linecolor=blue]{-}{h0}{h1}
\ncline[linecolor=blue]{->}{h1}{box}
\end{pspicture}
\end{slide}
+% contents
+
\begin{slide}
\headphd
\begin{minipage}{4.0cm}
\begin{center}
C-Si dimers (dumbbells)\\[-0.1cm]
- on Si interstitial sites
+ on Si lattice sites
\end{center}
\end{minipage}
\hspace{0.1cm}
\begin{slide}
+\headphd
+{\large\bf
+ Outline
+}
+
+ \begin{itemize}
+ {\color{gray}
+ \item Introduction / Motivation
+ \item Assumed SiC precipitation mechanisms / Controversy
+ }
+ \item Utilized simulation techniques
+ \begin{itemize}
+ \item Molecular dynamics (MD) simulations
+ \item Density functional theory (DFT) calculations
+ \end{itemize}
+ \item Simulation results
+ \begin{itemize}
+ \item C and Si self-interstitial point defects in silicon
+ \item Silicon carbide precipitation simulations
+ \end{itemize}
+ \item Summary / Conclusion
+ \end{itemize}
+
+\end{slide}
+
+\begin{slide}
+
\headphd
{\large\bf
Utilized computational methods
\hrule
\begin{itemize}
\item Code: \textsc{vasp}
-\item Plane wave basis set
+\item Plane wave basis set | $E_{\text{cut}}=\unit[300]{eV}$
%$\displaystyle
%\Phi_i=\sum_{|G+k|<G_{\text{cut}}} c_{i,k+G} \exp{\left(i(k+G)r\right)}
%$\\
\begin{itemize}
\item Stretched coherent SiC structures\\
$\Rightarrow$ Precipitation process involves {\color{blue}\cs}
-\item Explains annealing behavior of high/low T C implantations
- \begin{itemize}
- \item Low T: highly mobile {\color{red}\ci}
- \item High T: stable configurations of {\color{blue}\cs}
- \end{itemize}
\item Role of \si{}
\begin{itemize}
\item Vehicle to rearrange \cs --- [\cs{} \& \si{} $\leftrightarrow$ \ci]
\ldots Si/SiC interface\\
\ldots within stretched coherent SiC structure
\end{itemize}
+\item Explains annealing behavior of high/low T C implantations
+ \begin{itemize}
+ \item Low T: highly mobile {\color{red}\ci}
+ \item High T: stable configurations of {\color{blue}\cs}
+ \end{itemize}
\end{itemize}
\vspace{0.2cm}
\centering
\end{slide}
-% skip high T / C conc ... only here!
+% skip high c conc results
\ifnum1=0
\begin{slide}
\footnotesize
-\begin{minipage}{6.5cm}
+\begin{minipage}{6.0cm}
\includegraphics[width=6.4cm]{12_pc_thesis.ps}
\end{minipage}
-\begin{minipage}{6.5cm}
+\begin{minipage}{6.0cm}
\includegraphics[width=6.4cm]{12_pc_c_thesis.ps}
\end{minipage}
\end{slide}
-% skipped high T / C conc
+% skip high c conc
\fi
+% for preparation
+%\fi
+
\begin{slide}
+\headphd
{\large\bf
- Summary / Outlook
+ Summary / Conclusions
}
-\small
+\scriptsize
-\begin{pspicture}(0,0)(12,1.0)
-\psframebox[fillstyle=gradient,gradbegin=hred,gradend=white,gradlines=1000,gradmidpoint=1.0,linestyle=none]{
-\begin{minipage}{11cm}
-{\color{black}Diploma thesis}\\
- \underline{Monte Carlo} simulation modeling the selforganization process\\
- leading to periodic arrays of nanometric amorphous SiC precipitates
+\framebox{
+\begin{minipage}{12.3cm}
+ \underline{Defects}
+ \begin{itemize}
+ \item DFT / EA
+ \begin{itemize}
+ \item Point defects excellently / fairly well described
+ by DFT / EA
+ \item C$_{\text{sub}}$ drastically underestimated by EA
+ \item EA predicts correct ground state:
+ C$_{\text{sub}}$ \& \si{} $>$ \ci{}
+ \item Identified migration path explaining
+ diffusion and reorientation experiments by DFT
+ \item EA fails to describe \ci{} migration:
+ Wrong path \& overestimated barrier
+ \end{itemize}
+ \item Combinations of defects
+ \begin{itemize}
+ \item Agglomeration of point defects energetically favorable
+ by compensation of stress
+ \item Formation of C-C unlikely
+ \item C$_{\text{sub}}$ favored conditions (conceivable in IBS)
+ \item \ci{} \hkl<1 0 0> $\leftrightarrow$ \cs{} \& \si{} \hkl<1 1 0>\\
+ Low barrier (\unit[0.77]{eV}) \& low capture radius
+ \end{itemize}
+ \end{itemize}
\end{minipage}
}
-\end{pspicture}\\[0.4cm]
-\begin{pspicture}(0,0)(12,2)
-\psframebox[fillstyle=gradient,gradbegin=hblue,gradend=white,gradmidpoint=1.0,gradlines=1000,linestyle=none]{
-\begin{minipage}{11cm}
-{\color{black}Doctoral studies}\\
- Classical potential \underline{molecular dynamics} simulations \ldots\\
- \underline{Density functional theory} calculations \ldots\\[0.2cm]
- \ldots on defect formation and SiC precipitation in Si
+
+\framebox{
+\begin{minipage}[t]{12.3cm}
+ \underline{Pecipitation simulations}
+ \begin{itemize}
+ \item High C concentration $\rightarrow$ amorphous SiC like phase
+ \item Problem of potential enhanced slow phase space propagation
+ \item Low T $\rightarrow$ C-Si \hkl<1 0 0> dumbbell dominated structure
+ \item High T $\rightarrow$ C$_{\text{sub}}$ dominated structure
+ \item High T necessary to simulate IBS conditions (far from equilibrium)
+ \item Precipitation by successive agglomeration of \cs (epitaxy)
+ \item \si{}: vehicle to form \cs{} \& supply of Si \& stress compensation
+ (stretched SiC, interface)
+ \end{itemize}
\end{minipage}
}
-\end{pspicture}\\[0.5cm]
-\begin{pspicture}(0,0)(12,3)
-\psframebox[fillstyle=solid,fillcolor=white,linestyle=solid]{
-\begin{minipage}{11cm}
-\vspace{0.2cm}
-{\color{black}\bf How to proceed \ldots}\\[0.1cm]
-MC $\rightarrow$ empirical potential MD $\rightarrow$ Ground-state DFT \ldots
-\begin{itemize}
- \renewcommand\labelitemi{$\ldots$}
- \item beyond LDA/GGA methods \& ground-state DFT
-\end{itemize}
-Investigation of structure \& structural evolution \ldots
-\begin{itemize}
- \renewcommand\labelitemi{$\ldots$}
- \item electronic/optical properties
- \item electronic correlations
- \item non-equilibrium systems
-\end{itemize}
-\end{minipage}
+
+\begin{center}
+{\color{blue}
+\framebox{Precipitation by successive agglomeration of \cs{}}
}
-\end{pspicture}\\[0.5cm]
+\end{center}
\end{slide}
\item Ralf Utermann (EDV)
\end{itemize}
+ \underline{Berlin/Brandenburg}
+ \begin{itemize}
+ \item PD Volker Eyert (Ref)
+ \end{itemize}
+
\underline{Helsinki}
\begin{itemize}
\item Prof. K. Nordlund (MD)
\item Dr. E. Rauls (DFT + SiC)
\end{itemize}
- \underline{Stuttgart}
\begin{center}
\framebox{
-\bf Thank you for your attention / invitation!
+\bf Thank you for your attention!
}
\end{center}
projects / lectures / latex.git / blobdiff