From: hackbard Date: Sat, 29 Oct 2011 09:42:39 +0000 (+0200) Subject: more ibs X-Git-Url: https://hackdaworld.org/gitweb/?a=commitdiff_plain;h=448bf217190b3d815e3d749631af50cbcbd21834;p=lectures%2Flatex.git more ibs --- diff --git a/posic/talks/mpi_app.tex b/posic/talks/mpi_app.tex index f3e3a12..9931ba1 100644 --- a/posic/talks/mpi_app.tex +++ b/posic/talks/mpi_app.tex @@ -309,9 +309,11 @@ Thermal conductivity [W/cmK] & 5.0 & 4.9 & 4.9 & 1.5 & 1.3 & 22 \\ \vspace{2pt} +\begin{center} {\color{gray} \emph{Silicon carbide --- Born from the stars, perfected on earth.} } +\end{center} \vspace{2pt} @@ -328,76 +330,61 @@ SiC thin film by MBE \& CVD \includegraphics[width=2.0cm]{cree.eps} \end{picture} -Alternative method: Ion beam synthesis of SiC in Si +\vspace{-0.4cm} + +Alternative approach: +Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0) +\scriptsize + +\begin{minipage}{6.5cm} \begin{itemize} - \item \underline{Sublimation growth using the modified Lely method} - \begin{itemize} - \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 \underline{Homoepitaxial growth using CVD} - \begin{itemize} - \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 - \end{itemize} - \item \underline{Heteroepitaxial growth of 3C-SiC on Si using CVD/MBE} - \begin{itemize} - \item Two steps: carbonization and growth - \item $T=650-1050 \, ^{\circ} \text{C}$ - \item SiC/Si lattice mismatch $\approx$ 20 \% - \item Quality and size not yet sufficient - \end{itemize} + \item \underline{Implantation step 1}\\ + 180 keV C$^+$, $D=7.9\times 10^{17}$ cm$^{-2}$, $T_{\text{i}}=500\,^{\circ}\mathrm{C}$\\[0.1cm] + Box-like distribution of equally sized \&\\ + epitaxially oriented SiC precipitates + + \item \underline{Implantation step 2}\\ + 180 keV C$^+$, $D=0.6\times 10^{17}$ cm$^{-2}$, $T_{\text{i}}=250\,^{\circ}\mathrm{C}$\\[0.1cm] + Destruction of SiC nanocrystals\\ + in growing amorphous interface layers + \item \underline{Annealing}\\ + $T=1250\,^{\circ}\mathrm{C}$, $t=10\,\text{h}$\\[0.1cm] + Homogeneous, stoichiometric SiC layer\\ + with sharp interfaces \end{itemize} +\end{minipage} +\begin{minipage}{0.3cm} +\hfill +\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} - \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)(-333,-175) - \begin{minipage}{5cm} - {\tiny - 1. Lid\\[-7pt] - 2. Heating\\[-7pt] - 3. Source\\[-7pt] - 4. Crucible\\[-7pt] - 5. Insulation\\[-7pt] - 6. Seed crystal - } - \end{minipage} - \end{picture} - \begin{picture}(0,0)(-230,-35) - \framebox{ - {\footnotesize\color{blue}\bf Hex: micropipes along c-axis} +\framebox{ + \begin{minipage}{6.3cm} + \begin{center} + {\color{blue} + Precipitation mechanism not yet fully understood! } - \end{picture} - \begin{picture}(0,0)(-230,-10) - \framebox{ - \begin{minipage}{3cm} - {\footnotesize\color{blue}\bf 3C-SiC fabrication\\ - less advanced} + \renewcommand\labelitemi{$\Rightarrow$} + \small + \underline{Understanding the SiC precipitation} + \begin{itemize} + \item significant technological progress in SiC thin film formation + \item perspectives for processes relying upon prevention of SiC precipitation + \end{itemize} + \end{center} \end{minipage} - } - \end{picture} +} \end{slide} -\end{document} -\ifnum1=0 - % contents \begin{slide} @@ -428,59 +415,8 @@ Alternative method: Ion beam synthesis of SiC in Si \end{slide} - \end{document} - -\begin{slide} - - {\large\bf - Fabrication of silicon carbide - } - - \small - - Alternative approach: - Ion beam synthesis (IBS) of burried 3C-SiC layers in Si\hkl(1 0 0) - \begin{itemize} - \item \underline{Implantation step 1}\\ - 180 keV C$^+$, $D=7.9\times 10^{17}$ cm$^{-2}$, $T_{\text{i}}=500\,^{\circ}\mathrm{C}$\\ - $\Rightarrow$ box-like distribution of equally sized - and epitactically oriented SiC precipitates - - \item \underline{Implantation step 2}\\ - 180 keV C$^+$, $D=0.6\times 10^{17}$ cm$^{-2}$, $T_{\text{i}}=250\,^{\circ}\mathrm{C}$\\ - $\Rightarrow$ destruction of SiC nanocrystals - in growing amorphous interface layers - \item \underline{Annealing}\\ - $T=1250\,^{\circ}\mathrm{C}$, $t=10\,\text{h}$\\ - $\Rightarrow$ homogeneous, stoichiometric SiC layer - with sharp interfaces - \end{itemize} - - \begin{minipage}{6.3cm} - \includegraphics[width=6cm]{ibs_3c-sic.eps}\\[-0.2cm] - {\tiny - XTEM micrograph of single crystalline 3C-SiC in Si\hkl(1 0 0) - } - \end{minipage} -\framebox{ - \begin{minipage}{6.3cm} - \begin{center} - {\color{blue} - Precipitation mechanism not yet fully understood! - } - \renewcommand\labelitemi{$\Rightarrow$} - \small - \underline{Understanding the SiC precipitation} - \begin{itemize} - \item significant technological progress in SiC thin film formation - \item perspectives for processes relying upon prevention of SiC precipitation - \end{itemize} - \end{center} - \end{minipage} -} - -\end{slide} +\ifnum1=0 \begin{slide}