finished polytypes slide

[lectures/latex.git] / posic / talks / seminar_2010.tex

diff --git a/posic/talks/seminar_2010.tex b/posic/talks/seminar_2010.tex
index fd742bb..1224040 100644 (file)
--- a/posic/talks/seminar_2010.tex
+++ b/posic/talks/seminar_2010.tex
@@ -172,14 +172,14 @@
 }
 
  \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}
@@ -191,47 +191,116 @@
 \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] & \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}
+
+{\tiny
+ Values for $T=300$ K
+}
+
+\begin{picture}(0,0)(-160,-155)
+ \includegraphics[width=7cm]{polytypes.eps}
+\end{picture}
+\begin{picture}(0,0)(-10,-185)
+ \includegraphics[width=3.8cm]{cubic_hex.eps}\\
+\end{picture}
+\begin{picture}(0,0)(-10,-175)
+ {\tiny cubic (twist)}
+\end{picture}
+\begin{picture}(0,0)(-60,-175)
+ {\tiny hexagonal (no twist)}
+\end{picture}
+\begin{pspicture}(0,0)(0,0)
+\psellipse[linecolor=green](5.7,3.03)(0.4,0.5)
+\end{pspicture}
+\begin{pspicture}(0,0)(0,0)
+\psellipse[linecolor=green](5.6,1.68)(0.4,0.2)
+\end{pspicture}
+\begin{pspicture}(0,0)(0,0)
+\psellipse[linecolor=red](10.7,1.13)(0.4,0.2)
+\end{pspicture}
+
+\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}