}
\begin{itemize}
- \item Fabrication of silicon carbide
- \item Precipitation model
+ \item Fabrication of silicon carbide and different polytypes
+ \item Precipitation model of 3C-SiC in Si
\item Utilized simulation techniques
\begin{itemize}
\item Molecular dynamics (MD) simulations
\item Density functional theory (DFT) calculations
\end{itemize}
- \item Point defects in silicon
+ \item C and Si self-interstitial point defects in silicon
\item Precipitation simulations
\item Summary / Conclusion / Outlook
\end{itemize}
\begin{slide}
{\large\bf
- Motivation
+ Polytypes of SiC
}
+
+ \vspace{4cm}
+
+ \small
+
+\begin{tabular}{l | c c c c c c}
+\hline
+ & 3C-SiC & 4H-SiC & 6H-SiC & Si & GaN & Diamond\\
+\hline
+Hardness [Mohs] & 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] & & & & & & \\
+Saturation drift velocity [] & & & & & & \\
+Electron mobility [] & & & & & & \\
+Hole mobility [] & & & & & & \\
+Thermal conductivity [] & & & & & & \\
+\hline
+\end{tabular}
+
+\begin{picture}(0,0)(-160,-155)
+ \includegraphics[width=7cm]{polytypes.eps}
+\end{picture}
+
+\end{slide}
+
+\begin{slide}
+
+ {\large\bf
+ Fabrication of silicon carbide
+ }
+
+ \small
\vspace{4pt}
SiC - \emph{Born from the stars, perfected on earth.}
-
+
\vspace{4pt}
- Herstellung d"unner SiC-Filme:
+ Conventional thin film SiC growth:
\begin{itemize}
- \item modifizierter Lely-Prozess
+ \item \underline{Sublimation growth using the modified Lely method}
\begin{itemize}
- \item Impfkristall mit $T=2200 \, ^{\circ} \text{C}$
- \item umgeben von polykristallinen SiC mit
- $T=2400 \, ^{\circ} \text{C}$
+ \item SiC single-crystalline seed at $T=1800 \, ^{\circ} \text{C}$
+ \item Surrounded by polycrystalline SiC in a graphite crucible\\
+ at $T=2100-2400 \, ^{\circ} \text{C}$
+ \item Deposition of supersaturated vapor on cooler seed crystal
\end{itemize}
- \item CVD Homoepitaxie
+ \item \underline{Homoepitaxial growth using CVD}
\begin{itemize}
- \item 'step controlled epitaxy' auf 6H-SiC-Substrat
- \item C$_3$H$_8$/SiH$_4$/H$_2$ bei $1500 \, ^{\circ} \text{C}$
- \item Winkel $\rightarrow$ 3C/6H/4H-SiC
- \item hohe Qualit"at aber limitiert durch\\
- Substratgr"o"se
+ \item Step-controlled epitaxy on off-oriented 6H-SiC substrates
+ \item C$_3$H$_8$/SiH$_4$/H$_2$ at $1100-1500 \, ^{\circ} \text{C}$
+ \item Angle, temperature $\rightarrow$ 3C/6H/4H-SiC
+ \item High quality but limited in size of substrates
\end{itemize}
- \item CVD/MBE Heteroepitaxie von 3C-SiC auf Si
+ \item \underline{Heteroepitaxial growth of 3C-SiC on Si using CVD/MBE}
\begin{itemize}
- \item 2 Schritte: Karbonisierung und Wachstum
+ \item Two steps: carbonization and growth
\item $T=650-1050 \, ^{\circ} \text{C}$
- \item Qualit"at/Gr"o"se noch nicht ausreichend
+ \item Quality and size not yet sufficient
\end{itemize}
\end{itemize}
- \begin{picture}(0,0)(-245,-50)
- \includegraphics[width=5cm]{6h-sic_3c-sic.eps}
+ \begin{picture}(0,0)(-280,-65)
+ \includegraphics[width=3.8cm]{6h-sic_3c-sic.eps}
+ \end{picture}
+ \begin{picture}(0,0)(-280,-55)
+ \begin{minipage}{5cm}
+ {\tiny
+ NASA: 6H-SiC and 3C-SiC LED\\[-7pt]
+ on 6H-SiC substrate
+ }
+ \end{minipage}
+ \end{picture}
+ \begin{picture}(0,0)(-265,-150)
+ \includegraphics[width=2.4cm]{m_lely.eps}
\end{picture}
- \begin{picture}(0,0)(-240,-35)
+ \begin{picture}(0,0)(-333,-175)
\begin{minipage}{5cm}
- {\scriptsize
- NASA: 6H-SiC LED und 3C-SiC LED\\[-6pt]
- nebeneinander auf 6H-SiC-Substrat
+ {\tiny
+ 1. Lid\\[-7pt]
+ 2. Heating\\[-7pt]
+ 3. Source\\[-7pt]
+ 4. Crucible\\[-7pt]
+ 5. Insulation\\[-7pt]
+ 6. Seed crystal
}
\end{minipage}
\end{picture}