X-Git-Url: https://hackdaworld.org/gitweb/?p=lectures%2Flatex.git;a=blobdiff_plain;f=posic%2Ftalks%2Fdefense.tex;h=bfd92d02b17584803e5572eb17ac4fe9f45a1131;hp=a8062e86cd38703c420e4980a4e21c592e9f22c8;hb=b72d5fabe9b016843d069c4478310ea67e76fc47;hpb=3f65cf44692d94497ff4a2ac366cb91b97ac3012

diff --git a/posic/talks/defense.tex b/posic/talks/defense.tex
index a8062e8..bfd92d0 100644
--- a/posic/talks/defense.tex
+++ b/posic/talks/defense.tex
@@ -122,6 +122,7 @@
 
 % layout check
 %\layout
+\ifnum1=0
 \begin{slide}
 \center
 {\Huge
@@ -134,6 +135,7 @@ F\\
 E\\
 }
 \end{slide}
+\fi
 
 % topic
 
@@ -142,23 +144,26 @@ E\\
 
  \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}
@@ -166,6 +171,9 @@ E\\
 % no vertical centering
 \centerslidesfalse
 
+% skip for preparation
+%\ifnum1=0
+
 % intro
 
 % motivation / properties / applications of silicon carbide
@@ -242,10 +250,13 @@ E\\
 
 \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)}
@@ -277,13 +288,13 @@ Thermal conductivity [W/cmK] & 5.0 & 4.9 & 4.9 & 1.5 & 1.3 & 22 \\
 \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}
@@ -322,12 +333,24 @@ SiC thin films by MBE \& CVD
   \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
 
@@ -350,36 +373,15 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0)
 \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}
 
@@ -387,7 +389,7 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0)
 
 \headphd
 {\large\bf
- Formation of epitaxial single crystalline 3C-SiC
+ IBS of epitaxial single crystalline 3C-SiC
 }
 
 \footnotesize
@@ -410,8 +412,13 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0)
 \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)
@@ -435,8 +442,8 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 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}
@@ -444,6 +451,8 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0)
 
 \end{slide}
 
+% contents
+
 \begin{slide}
 
 \headphd
@@ -495,7 +504,7 @@ $\rho^*_{\text{Si}}=\unit[97]{\%}$
  \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}
@@ -705,6 +714,33 @@ r = \unit[2--4]{nm}
 
 \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
@@ -753,7 +789,7 @@ NpT (isothermal-isobaric) | Berendsen thermostat/barostat\\
 \hrule
 \begin{itemize}
 \item Code: \textsc{vasp}
-\item Plane wave basis set
+\item Plane wave basis set | $E_{\text{cut}}=\unit[300]{eV}$
 %$\displaystyle
 %\Phi_i=\sum_{|G+k|<G_{\text{cut}}} c_{i,k+G} \exp{\left(i(k+G)r\right)}
 %$\\
@@ -2079,11 +2115,6 @@ equilibrium properties
 \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]
@@ -2092,6 +2123,11 @@ $\Rightarrow$ Precipitation process involves {\color{blue}\cs}
              \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
@@ -2109,7 +2145,7 @@ High T $\leftrightarrow$ IBS conditions far from equilibrium\\
 
 \end{slide}
 
-% skip high T / C conc ... only here!
+% skip high c conc results
 \ifnum1=0
 
 \begin{slide}
@@ -2120,10 +2156,10 @@ High T $\leftrightarrow$ IBS conditions far from equilibrium\\
 
 \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}
 
@@ -2178,56 +2214,71 @@ High C \& low T implants
 
 \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}
 
@@ -2249,6 +2300,11 @@ Investigation of structure \& structural evolution \ldots
   \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)
@@ -2266,10 +2322,9 @@ Investigation of structure \& structural evolution \ldots
   \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}