From 2b740e5bda4a90139d952a5efc5345e62747f955 Mon Sep 17 00:00:00 2001 From: hackbard Date: Fri, 29 Apr 2011 17:00:22 +0200 Subject: [PATCH] started initial part of prec models --- bibdb/bibdb.bib | 39 +++++++++++++++++++++++++++++++++++ posic/thesis/sic.tex | 48 ++++++++++++++++++++++++++++++++++---------- 2 files changed, 76 insertions(+), 11 deletions(-) diff --git a/bibdb/bibdb.bib b/bibdb/bibdb.bib index 076bf0e..c7019b9 100644 --- a/bibdb/bibdb.bib +++ b/bibdb/bibdb.bib @@ -118,6 +118,7 @@ pages = "827--835", month = mar, year = "2003", + URL = "http://www.springerlink.com/content/jr8xj33mqc5vpwwj/", notes = "dual implantation, sic prec enhanced by vacancies, precipitation by interstitial and substitutional carbon, both mechanisms explained + refs", @@ -4554,6 +4555,21 @@ eprint = "http://journals.cambridge.org/article_S1946427400543681", } +@Article{mukashev82, + title = "Defects in Carbon-Implanted Silicon", + author = "Bulat N. Mukashev and Alexey V. Spitsyn and Noboru + Fukuoka and Haruo Saito", + journal = "Japanese Journal of Applied Physics", + volume = "21", + number = "Part 1, No. 2", + pages = "399--400", + numpages = "1", + year = "1982", + URL = "http://jjap.jsap.jp/link?JJAP/21/399/", + doi = "10.1143/JJAP.21.399", + publisher = "The Japan Society of Applied Physics", +} + @Article{puska98, title = "Convergence of supercell calculations for point defects in semiconductors: Vacancy in silicon", @@ -4592,3 +4608,26 @@ URL = "http://link.aip.org/link/?JAP/77/2978/1", doi = "10.1063/1.358714", } + +@Article{romano-rodriguez96, + title = "Detailed analysis of [beta]-Si{C} formation by high + dose carbon ion implantation in silicon", + journal = "Materials Science and Engineering B", + volume = "36", + number = "1-3", + pages = "282--285", + year = "1996", + note = "European Materials Research Society 1995 Spring + Meeting, Symposium N: Carbon, Hydrogen, Nitrogen, and + Oxygen in Silicon and in Other Elemental + Semiconductors", + ISSN = "0921-5107", + doi = "DOI: 10.1016/0921-5107(95)01283-4", + URL = "http://www.sciencedirect.com/science/article/B6TXF-3VR7691-25/2/995fd57b9e5c1100558f80c472620408", + author = "A. Romano-Rodriguez and C. Serre and L. Calvo-Barrio + and A. Pérez-Rodríguez and J. R. Morante and R. Kögler + and W. Skorupa", + keywords = "Silicon", + keywords = "Ion implantation", + notes = "incoherent 3c-sic precipitate", +} diff --git a/posic/thesis/sic.tex b/posic/thesis/sic.tex index c10fe17..8783989 100644 --- a/posic/thesis/sic.tex +++ b/posic/thesis/sic.tex @@ -345,13 +345,29 @@ While not being compatible to very-large-scale integration technology, C concent \label{section:assumed_prec} Although high-quality films of single-crystalline 3C-SiC can be produced by means of \ac{IBS} the precipitation mechanism in bulk Si is not yet fully understood. -Indeed, closely investigating the large amount of literature reveals controversial ideas of SiC formation assumed by the respective authors, which are reviewed in more detail in the following. +Indeed, closely investigating the large amount of literature reveals controversial ideas of SiC formation, which are reviewed in more detail in the following. + +\begin{figure}[ht] +\begin{center} +\subfigure[]{\label{fig:sic:hrem:c-si}\includegraphics[width=0.48\columnwidth]{tem_c-si-db.eps}} +\subfigure[]{\label{fig:sic:hrem:sic}\includegraphics[width=0.48\columnwidth]{tem_3c-sic.eps}} +\end{center} +\caption{High resolution transmission electron microscopy (HREM) micrographs\cite{lindner99_2} of agglomerates of C-Si dimers showing dark contrasts and otherwise undisturbed Si lattice fringes (a) and equally sized Moir\'e patterns indicating 3C-SiC precipitates (b).} +\label{fig:sic:hrem} +\end{figure} + +\ac{HREM} investigations of C-implanted Si at room temperature followed by \ac{RTA} show the formation of C-Si dumbbell agglomerates, which are stable up to annealing temperatures of about \unit[700-800]{$\circ$C}, and a transformation into 3C-SiC precipitates at higher temperatures \cite{werner96,werner97}. +The precipitates with diamateres between \unit[2]{nm} and \unit[5]{nm} are incorporated in the Si matrix without any remarkable strain fields, which is explained by the nearly equal atomic density of C-Si agglomerates and the SiC unit cell. +Implantations at \unit[500]{$\circ$C} likewise suggest an initial formation of C-Si dumbbells on regular Si lattice sites, which agglomerate into large clusters \cite{lindner99_2}. +The agglomerates of such dimers, which do not generate lattice strain but lead to a local increase of the lattice potential \cite{werner96}, are indicated by dark contrasts and otherwise undisturbed Si lattice fringes in \ac{HREM}, as can be seen in Fig.~\ref{fig:sic:hrem:c-si}. +A topotactic transformation into a 3C-SiC precipitate occurs once a critical radius of \unit[2]{nm} to \unit[4]{nm} is reached. +The precipitation is manifested by the disappearance of the dark contrasts in favor of Moir\'e patterns (Fig.~\ref{fig:sic:hrem:sic}) due to the lattice mismatch of \unit[20]{\%} of the 3C-SiC precipitate and the Si host. +The insignificantly lower Si density of SiC of approximately \unit[3]{\%} compared to c-Si results in the emission of only a few excess Si atoms. -\ac{HREM} studies \cite{werner96,werner97,eichhorn99,lindner99_2,koegler03} suggest the formation of C-Si dimers (dumbbells) on regular Si lattice sites, which agglomerate into large clusters indicated by dark contrasts and otherwise undisturbed Si lattice fringes in HREM, as can be seen in Fig.~\ref{fig:hrem:c-si}. -A topotactic transformation into a 3C-SiC precipitate occurs once a critical radius of 2 nm to 4 nm is reached, which is manifested by the disappearance of the dark contrasts in favor of Moir\'e patterns (Fig.~\ref{fig:hrem:sic}) due to the lattice mismatch of \unit[20]{\%} of the 3C-SiC precipitate and c-Si. +The formation of SiC by a preceeding agglomeration of C-Si dumbbells is supported by studies ... \cite{koegler03,eichhorn99} + -The insignificantly lower Si density of SiC ($\approx \unit[4]{\%}$) compared to c-Si results in the emission of only a few excess Si atoms. In contrast, investigations of strained Si$_{1-y}$C$_y$/Si heterostructures formed by MBE\cite{strane94,guedj98}, which incidentally involve the formation of SiC nanocrystallites, suggest an initial coherent precipitation by agglomeration of substitutional instead of interstitial C. @@ -368,18 +384,28 @@ The formation of substitutional C, however, is accompanied by Si self-interstiti Both processes are believed to compensate one another. -cites: - -ibs, c-si agglom: werner96,werner97,eichhorn99,lindner99_2,koegler03 -ibs, c sub: nejim95 -ibs, indicated c sub: martin90 + conclusions reeson8x, eichhorn02 -hetero, coherent sic by sub c: strane94,guedj98 +%cites: -more: taylor93, kitabatake contraction along 110, koegler03 +% continue with strane94 and werner96 +%ibs, c-si agglom: werner96,werner97,eichhorn99,lindner99_2,koegler03 +%hetero, coherent sic by sub c: strane94,guedj98 +%ibs, c sub: nejim95 +%ibs, indicated c sub: martin90 + conclusions reeson8x, eichhorn02 +%more: taylor93, kitabatake contraction along 110, koegler03 +%taylor93: sic prec only/more_easy if self interstitials are present % -> skorupa 3.2: c sub vs sic prec +% remember! +% werner96/7: rt implants followed by rta < 800: C-Si db aggloms | > 800: 3C-SiC +% taylor93: si_i reduces interfacial energy (explains metastability) of sic/si +% eichhorn02: high imp temp more efficient than postimp treatment + +% todo +% add sharp iface image! + + on surface ... md contraction along 110 ... kitabatake ... and ref in lindner ... rheed from si to sic ... in ibs ... lindner and skorupa ... -- 2.39.2