X-Git-Url: https://hackdaworld.org/gitweb/?a=blobdiff_plain;f=posic%2Ftalks%2Fseminar_2008.tex;h=69560302453bf8438b00d3af2c847423cb1b31cf;hb=62931e25b418b7223cc79d6f919c24d90c7d2573;hp=2d2218e87122c23cf1f18f39fa77be45634c9a8f;hpb=a63663eef597c796faf6a3882166a5d66ce4e6f3;p=lectures%2Flatex.git diff --git a/posic/talks/seminar_2008.tex b/posic/talks/seminar_2008.tex index 2d2218e..6956030 100644 --- a/posic/talks/seminar_2008.tex +++ b/posic/talks/seminar_2008.tex @@ -271,13 +271,47 @@ Die Alternative: Ionenstrahlsynthese + {\small + \begin{itemize} - \item Implantation: - 180 keV C$^+\rightarrow$ Si, $D=8.5 \times 10^{17}$ cm$^{-2}$, - $T_{\text{i}}=450 \, ^{\circ} \text{C}$ - \item Temperschritt: - $T=1250 \, ^{\circ} \text{C}$, $t=??\text{ h}$ + \item Implantation 1: + 180 keV C$^+\rightarrow$ FZ-Si(100), + $D=7.9 \times 10^{17}$ cm$^{-2}$, + $T_{\text{i}}=500 \, ^{\circ} \text{C}$\\ + epitaktisch orientierte 3C-SiC Ausscheidungen + in kastenf"ormigen Bereich,\\ + eingeschlossen in a-Si:C + \item Implantation 2: + 180 keV C$^+\rightarrow$ FZ-Si(100), + $D=0.6 \times 10^{17}$ cm$^{-2}$, + $T_{\text{i}}=250 \, ^{\circ} \text{C}$\\ + Zerst"orung einzelner SiC Ausscheidungen + in gr"o"ser werdenden amorphen Grenzschichten + \item Tempern: + $T=1250 \, ^{\circ} \text{C}$, $t=10\text{ h}$\\ + Homogene st"ochiometrische 3C-SiC Schicht mit + scharfen Grenzfl"achen \end{itemize} + + \begin{minipage}{6.3cm} + \includegraphics[width=6.3cm]{ibs_3c-sic.eps} + \end{minipage} + \hspace*{0.2cm} + \begin{minipage}{6.5cm} + \vspace*{2.3cm} + {\scriptsize + Querschnitts-TEM-Aufnahme einer einkristallinen vergrabenen + 3C-SiC-Schicht.\\ + (a) Hellfeldaufnahme\\ + (b) 3C-SiC(111) Dunkelfeldaufnahme\\ + } + \end{minipage} + + \vspace{0.2cm} + + Entscheidende Parameter: Dosis und Implantationstemperatur + +} \end{slide} @@ -321,10 +355,24 @@ SiC-Ausscheidungsvorgang } - \vspace{64pt} + Hochaufl"osungs-TEM:\\[-0.5cm] - Hier die aus experimentellen Untersuchungen heraus vermuteten - Ausscheidungsvorgaenge rein. + \begin{minipage}{3.3cm} + \includegraphics[width=3.3cm]{tem_c-si-db.eps} + \end{minipage} + \begin{minipage}{9cm} + Bereich oberhalb des Implantationsmaximums\\ + Wolkenstruktur "uberlagert auf ungest"orten Si-Muster\\ + $\rightarrow$ C-Si Dumbbells + \end{minipage} + \begin{minipage}{3.3cm} + \includegraphics[width=3.3cm]{tem_3c-sic.eps} + \end{minipage} + \begin{minipage}{9cm} + Bereich ums Implantationsmaximum\\ + Moir\'e-Kontrast-Muster\\ + $\rightarrow$ inkoh"arente 3C-SiC-Ausscheidungen in c-Si-Matrix + \end{minipage} \end{slide} @@ -575,23 +623,18 @@ \small - \begin{minipage}{4cm} + \begin{minipage}{5.5cm} \begin{itemize} \item $E_f=0.47$ eV - \item Very often observed - \item Most energetically\\ - favorable configuration - \item Experimental\\ - evidence [6] + \item sehr h"aufig beobachtet + \item energetisch g"unstigste\\ Konfiguration + \item experimentelle und theoretische Hinweise + f"ur die Existenz dieser Konfiguration \end{itemize} - \vspace{24pt} - {\tiny - [6] G. D. Watkins and K. L. Brower,\\ - Phys. Rev. Lett. 36 (1976) 1329. - } + \includegraphics[width=5.6cm]{c_in_si_100.ps} \end{minipage} - \begin{minipage}{8cm} - \includegraphics[width=9cm]{100-c-si-db_s.eps} + \begin{minipage}{7cm} + \includegraphics[width=8cm]{100-c-si-db_s.eps} \end{minipage} \end{slide} @@ -633,8 +676,8 @@ \end{itemize} }}}} \rput(3.5,1){\rnode{cool}{\psframebox[fillstyle=solid,fillcolor=lbb]{ - \parbox{3.5cm}{ - Abk"uhlen auf $20\, ^{\circ}\textrm{C}$ + \parbox{5.0cm}{ + Nach 100 ps abk"uhlen auf $20\, ^{\circ}\textrm{C}$ }}}} \ncline[]{->}{init}{insert} \ncline[]{->}{insert}{cool} @@ -651,8 +694,6 @@ \end{slide} -\end{document} - \begin{slide} {\large\bf @@ -662,47 +703,57 @@ \includegraphics[width=6.3cm]{pc_si-c_c-c.eps} \includegraphics[width=6.3cm]{pc_si-si.eps} - \begin{minipage}[t]{6.3cm} - \tiny - \begin{itemize} - \item C-C peak at 0.15 nm similar to next neighbour distance of graphite - or diamond\\ - $\Rightarrow$ Formation of strong C-C bonds - (almost only for high C concentrations) - \item Si-C peak at 0.19 nm similar to next neighbour distance in 3C-SiC - \item C-C peak at 0.31 nm equals C-C distance in 3C-SiC\\ - (due to concatenated, differently oriented - <100> dumbbell interstitials) - \item Si-Si shows non-zero g(r) values around 0.31 nm like in 3C-SiC\\ - and a decrease at regular distances\\ - (no clear peak, - interval of enhanced g(r) corresponds to C-C peak width) - \end{itemize} - \end{minipage} - \begin{minipage}[t]{6.3cm} - \tiny - \begin{itemize} - \item Low C concentration (i.e. $V_1$): - The <100> dumbbell configuration - \begin{itemize} - \item is identified to stretch the Si-Si next neighbour distance - to 0.3 nm - \item is identified to contribute to the Si-C peak at 0.19 nm - \item explains further C-Si peaks (dashed vertical lines) - \end{itemize} - $\Rightarrow$ C atoms are first elements arranged at distances - expected for 3C-SiC\\ - $\Rightarrow$ C atoms pull the Si atoms into the right - configuration at a later stage - \item High C concentration (i.e. $V_2$ and $V_3$): - \begin{itemize} - \item High amount of damage introduced into the system - \item Short range order observed but almost no long range order - \end{itemize} - $\Rightarrow$ Start of amorphous SiC-like phase formation\\ - $\Rightarrow$ Higher temperatures required for proper SiC formation - \end{itemize} - \end{minipage} + \vspace{-0.1cm} + + \footnotesize + \underline{C-C, 0.15 nm}:\\ + NN-Abstand in Graphit/Diamant\\ + $\Rightarrow$ starke C-C Bindungen bei hohen Konz.\\ + \underline{Si-C, 0.19 nm}:\\ + NN-Abstand in 3C-SiC\\ + \underline{C-C, 0.31 nm}:\\ + C-C Abstand in 3C-SiC\\ + vekettete, verschieden orientierte 100 C-Si DBs\\ + \underline{Si-Si, $\sim$ 0.31 nm}:\\ + g(r) erh"oht, Si-Si in 3C-SiC\\ + Intervall entspricht C-C Peakbreite\\ + Abfall bei regul"aren Abst"anden + + \begin{picture}(0,0)(-175,-40) + \includegraphics[width=4.0cm]{conc_100_c-si-db_02.eps} + \end{picture} + \begin{picture}(0,0)(-278,-10) + \includegraphics[width=4.0cm]{conc_100_c-si-db_01.eps} + \end{picture} + + \end{slide} + + \begin{slide} + + {\large\bf + Simulationen zum Ausscheidungsvorgang + } + + \includegraphics[width=6.3cm]{pc_si-c_c-c.eps} + \includegraphics[width=6.3cm]{c_in_si_100.ps} + + \footnotesize + + \underline{Niedrige C-Konzentration ($V_1$)}: + 100 Dumbbell-Konfiguration + \begin{itemize} + \item dehnt Si-Si NN-Abstand auf 0.3 nm + \item Beitrag zum Si-C Peak bei 0.19 nm + \item erkl"art weitere Si-C Peaks (gestrichelte Linien) + \end{itemize} + $\Rightarrow$ C-Atome als erstes im erwarteten 3C-SiC-Abstand + \underline{Hohe C-Konzentration ($V_2$ und $V_3$)}: + \begin{itemize} + \item High amount of damage introduced into the system + \item Short range order observed but almost no long range order + \end{itemize} + $\Rightarrow$ Start of amorphous SiC-like phase formation\\ + $\Rightarrow$ Higher temperatures required for proper SiC formation \end{slide}