From: hackbard Date: Mon, 19 Sep 2011 13:34:52 +0000 (+0200) Subject: more on sic X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c99f610aabb097a64ddcb1656798fd2d59c958a0;p=lectures%2Flatex.git more on sic --- diff --git a/posic/thesis/sic.tex b/posic/thesis/sic.tex index 73c0e25..fb7fc46 100644 --- a/posic/thesis/sic.tex +++ b/posic/thesis/sic.tex @@ -268,9 +268,11 @@ In another study~\cite{serre95} high dose C implantations were performed at room Implantations at room temperature lead to the formation of a buried amorphous carbide layer in addition to a thin C-rich film at the surface, which is attributed to the migration of C atoms towards the surface. In contrast, implantations at elevated temperatures result in the exclusive formation of a buried layer consisting of 3C-SiC precipitates epitaxially aligned to the Si host, which obviously is more favorable than the C migration towards the surface. Annealing at temperatures up to \unit[1150]{$^{\circ}$C} does not alter the C profile. -Instead defect annihilation is observed and the C-rich surface layer of the room temperature implant turns into a layer consisting of SiC precipitates, which, however, are not aligned with the Si matrix indicating a mechanism different to the one of the direct formation for the high-temperature implantation. +Instead, defect annihilation is observed and the C-rich surface layer of the room temperature implant turns into a layer consisting of SiC precipitates, which, however, are not aligned with the Si matrix indicating a mechanism different to the one of the direct formation for the high-temperature implantation. -Based on these findings and extensive TEM investigations, a recipe was developed to form buried layers of single-crystalline SiC featuring an improved interface and crystallinity~\cite{lindner99,lindner01,lindner02}. +Based on these findings% +% and extensive TEM investigations +, a recipe was developed to form buried layers of single-crystalline SiC featuring an improved interface and crystallinity~\cite{lindner99,lindner01,lindner02}. Therefore, the dose must not exceed the stoichiometry dose, i.e.\ the dose corresponding to \unit[50]{at.\%} C concentration at the implantation peak. Otherwise clusters of C are formed, which cannot be dissolved during post-implantation annealing at moderate temperatures below the Si melting point~\cite{lindner96,calcagno96}. Annealing should be performed for \unit[5--10]{h} at \unit[1250]{$^{\circ}$C} to enable the redistribution from the as-implanted Gaussian into a box-like C depth profile~\cite{lindner95}.