X-Git-Url: https://hackdaworld.org/gitweb/?p=lectures%2Flatex.git;a=blobdiff_plain;f=posic%2Ftalks%2Fdefense.tex;h=2ae5461209d75b91dc221065859efd36b3ac678e;hp=a8062e86cd38703c420e4980a4e21c592e9f22c8;hb=e3b7278cc861f9eda107e72ebd8f07f90056c3a8;hpb=3f65cf44692d94497ff4a2ac366cb91b97ac3012 diff --git a/posic/talks/defense.tex b/posic/talks/defense.tex index a8062e8..2ae5461 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 @@ -238,58 +246,9 @@ E\\ \end{slide} -% motivation - -\begin{slide} - - {\large\bf - Polytypes of SiC\\[0.4cm] - } - -\includegraphics[width=3.8cm]{cubic_hex.eps}\\ -\begin{minipage}{1.9cm} -{\tiny cubic (twist)} -\end{minipage} -\begin{minipage}{2.9cm} -{\tiny hexagonal (no twist)} -\end{minipage} - -\begin{picture}(0,0)(-150,0) - \includegraphics[width=7cm]{polytypes.eps} -\end{picture} - -\vspace{0.6cm} - -\footnotesize - -\begin{tabular}{l c c c c c c} -\hline - & 3C-SiC & 4H-SiC & 6H-SiC & Si & GaN & Diamond\\ -\hline -Hardness [Mohs] & \multicolumn{3}{c}{------ 9.6 ------}& 6.5 & - & 10 \\ -Band gap [eV] & 2.36 & 3.23 & 3.03 & 1.12 & 3.39 & 5.5 \\ -Break down field [$10^6$ V/cm] & 4 & 3 & 3.2 & 0.6 & 5 & 10 \\ -Saturation drift velocity [$10^7$ cm/s] & 2.5 & 2.0 & 2.0 & 1 & 2.7 & 2.7 \\ -Electron mobility [cm$^2$/Vs] & 800 & 900 & 400 & 1100 & 900 & 2200 \\ -Hole mobility [cm$^2$/Vs] & 320 & 120 & 90 & 420 & 150 & 1600 \\ -Thermal conductivity [W/cmK] & 5.0 & 4.9 & 4.9 & 1.5 & 1.3 & 22 \\ -\hline -\end{tabular} - -\begin{pspicture}(0,0)(0,0) -\psellipse[linecolor=green](5.7,2.10)(0.4,0.5) -\end{pspicture} -\begin{pspicture}(0,0)(0,0) -\psellipse[linecolor=green](5.6,0.92)(0.4,0.2) -\end{pspicture} -\begin{pspicture}(0,0)(0,0) -\psellipse[linecolor=red](10.45,0.45)(0.4,0.2) -\end{pspicture} - -\end{slide} - % fabrication +\ifnum1=0 \begin{slide} \headphd @@ -322,12 +281,24 @@ SiC thin films by MBE \& CVD \includegraphics[width=2.0cm]{cree.eps} \end{picture} -\vspace{-0.2cm} +\vspace{-0.5cm} -Alternative approach: +%\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} + +{\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 @@ -358,36 +329,25 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0) \end{center} \end{minipage} -\end{slide} - -% contents - -\begin{slide} - -\headphd -{\large\bf - Outline -} - - \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} +%\begin{minipage}{5.5cm} +%\begin{center} +%{\footnotesize +%No surface bending effects\\ +%High areal homogenity\\[0.1cm] +%$\Downarrow$\\[0.1cm] +%Synthesis of large area SiC films possible +%} +%\end{center} +%\end{minipage} \end{slide} +\fi \begin{slide} \headphd {\large\bf - Formation of epitaxial single crystalline 3C-SiC + IBS of epitaxial single crystalline 3C-SiC } \footnotesize @@ -401,7 +361,7 @@ Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0) $\Rightarrow$ Epitaxial {\color{blue}3C-SiC} layer \& {\color{blue}precipitates} \item \underline{Implantation step 2}\\[0.1cm] - Little remaining dose | \unit[180]{keV} | \degc{250}\\ + Low remaining amount of dose | \unit[180]{keV} | \degc{250}\\ $\Rightarrow$ Destruction/Amorphization of precipitates at layer interface \item \underline{Annealing}\\[0.1cm] @@ -410,8 +370,13 @@ 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 +400,8 @@ 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} @@ -495,7 +460,7 @@ $\rho^*_{\text{Si}}=\unit[97]{\%}$ \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} @@ -673,7 +638,7 @@ r = \unit[2--4]{nm} \begin{itemize} \item High-temperature implantation {\tiny\color{gray}/Nejim~et~al./} \begin{itemize} - \item C incorporated {\color{blue}substitutionally} on regular Si lattice sites + \item {\color{blue}Substitutionally} incorporated C on regular Si lattice sites \item \si{} reacting with further C in cleared volume \end{itemize} \item Annealing behavior {\tiny\color{gray}/Serre~et~al./} @@ -683,10 +648,10 @@ r = \unit[2--4]{nm} \end{itemize} $\Rightarrow$ mobile {\color{red}\ci} opposed to stable {\color{blue}\cs{}} configurations -\item Strained silicon \& Si/SiC heterostructures +\item Strained silicon \& Si$_{1-y}$C$_y$ heterostructures {\tiny\color{gray}/Strane~et~al./Guedj~et~al./} \begin{itemize} - \item {\color{blue}Coherent} SiC precipitates (tensile strain) + \item Initial {\color{blue}coherent} SiC precipitates (tensile strain) \item Incoherent SiC (strain relaxation) \end{itemize} \end{itemize} @@ -705,6 +670,35 @@ r = \unit[2--4]{nm} \begin{slide} +% contents + +\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 +747,7 @@ 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| $\leftrightarrow$ \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 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 Increased participation of \cs{} in the precipitation process + \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}\bf +\framebox{Precipitation by successive agglomeration of \cs{}} } -\end{pspicture}\\[0.5cm] +\end{center} \end{slide} \begin{slide} - {\large\bf - Acknowledgements - } +\headphd +{\large\bf + Acknowledgements +} \vspace{0.1cm} @@ -2245,35 +2250,87 @@ Investigation of structure \& structural evolution \ldots \underline{Augsburg} \begin{itemize} - \item Prof. B. Stritzker (accomodation at EP \RM{4}) - \item Ralf Utermann (EDV) + \item Prof. B. Stritzker + \item Ralf Utermann \end{itemize} \underline{Helsinki} \begin{itemize} - \item Prof. K. Nordlund (MD) + \item Prof. K. Nordlund \end{itemize} \underline{Munich} \begin{itemize} - \item Bayerische Forschungsstiftung (financial support) + \item Bayerische Forschungsstiftung \end{itemize} \underline{Paderborn} \begin{itemize} - \item Prof. J. Lindner (SiC) - \item Prof. G. Schmidt (DFT + financial support) - \item Dr. E. Rauls (DFT + SiC) + \item Prof. J. Lindner + \item Prof. G. Schmidt + \item Dr. E. Rauls \end{itemize} - \underline{Stuttgart} +\vspace{ 0.2cm} + \begin{center} \framebox{ -\bf Thank you for your attention / invitation! +\normalsize\bf Thank you for your attention! } \end{center} \end{slide} +\begin{slide} + +\headphd + {\large\bf + Polytypes of SiC\\[0.6cm] + } + +\vspace{0.6cm} + +\includegraphics[width=3.8cm]{cubic_hex.eps}\\ +\begin{minipage}{1.9cm} +{\tiny cubic (twist)} +\end{minipage} +\begin{minipage}{2.9cm} +{\tiny hexagonal (no twist)} +\end{minipage} + +\begin{picture}(0,0)(-150,0) + \includegraphics[width=7cm]{polytypes.eps} +\end{picture} + +\vspace{0.6cm} + +\footnotesize + +\begin{tabular}{l c c c c c c} +\hline + & 3C-SiC & 4H-SiC & 6H-SiC & Si & GaN & Diamond\\ +\hline +Hardness [Mohs] & \multicolumn{3}{c}{------ 9.6 ------}& 6.5 & - & 10 \\ +Band gap [eV] & 2.36 & 3.23 & 3.03 & 1.12 & 3.39 & 5.5 \\ +Break down field [$10^6$ V/cm] & 4 & 3 & 3.2 & 0.6 & 5 & 10 \\ +Saturation drift velocity [$10^7$ cm/s] & 2.5 & 2.0 & 2.0 & 1 & 2.7 & 2.7 \\ +Electron mobility [cm$^2$/Vs] & 800 & 900 & 400 & 1100 & 900 & 2200 \\ +Hole mobility [cm$^2$/Vs] & 320 & 120 & 90 & 420 & 150 & 1600 \\ +Thermal conductivity [W/cmK] & 5.0 & 4.9 & 4.9 & 1.5 & 1.3 & 22 \\ +\hline +\end{tabular} + +\begin{pspicture}(0,0)(0,0) +\psellipse[linecolor=green](5.7,2.05)(0.4,0.50) +\end{pspicture} +\begin{pspicture}(0,0)(0,0) +\psellipse[linecolor=green](5.6,0.89)(0.4,0.20) +\end{pspicture} +\begin{pspicture}(0,0)(0,0) +\psellipse[linecolor=red](10.45,0.42)(0.4,0.20) +\end{pspicture} + +\end{slide} + \end{document}