From: hackbard Date: Mon, 26 Sep 2011 09:55:43 +0000 (+0200) Subject: again commas X-Git-Url: https://hackdaworld.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cec75d86d82183ec6452ae6cb84eefdfba37a0fe;p=lectures%2Flatex.git again commas --- diff --git a/posic/thesis/sic.tex b/posic/thesis/sic.tex index 9be1f9a..808734f 100644 --- a/posic/thesis/sic.tex +++ b/posic/thesis/sic.tex @@ -415,7 +415,7 @@ The precipitation mechanism based on a preceding dumbbell agglomeration as indic The incorporated C atoms form C-Si dumbbells on regular Si lattice sites. With increasing dose and proceeding time the highly mobile dumbbells agglomerate into large clusters. Finally, when the cluster size reaches a critical radius, the high interfacial energy due to the 3C-SiC/c-Si lattice misfit is overcome and precipitation occurs. -Due to the slightly lower silicon density of 3C-SiC excessive silicon atoms exist, which will most probably end up as self-interstitials in the c-Si matrix since there is more space than in 3C-SiC. +Due to the slightly lower silicon density of 3C-SiC, excessive silicon atoms exist, which will most probably end up as self-interstitials in the c-Si matrix since there is more space than in 3C-SiC. In contrast, IR spectroscopy and HREM investigations on the thermal stability of strained Si$_{1-y}$C$_y$/Si heterostructures formed by solid-phase epitaxy (SPE)~\cite{strane94} and MBE~\cite{guedj98}, which finally involve the incidental formation of SiC nanocrystallites, suggest a coherent initiation of precipitation by agglomeration of substitutional instead of interstitial C. These experiments show that the C atoms, which are initially incorporated substitutionally at regular lattice sites, form C-rich clusters maintaining coherency with the Si lattice during annealing above a critical temperature prior to the transition into incoherent 3C-SiC precipitates. @@ -424,7 +424,7 @@ Coherency is lost once the increasing strain energy of the stretched SiC structu Estimates of the SiC/Si interfacial energy~\cite{taylor93} and the consequent critical size correspond well with the experimentally observed precipitate radii within these studies. This different mechanism of precipitation might be attributed to the respective method of fabrication. -While in CVD and MBE, surface effects need to be taken into account, SiC formation during IBS takes place in the bulk of the Si crystal. +While in CVD and MBE surface effects need to be taken into account, SiC formation during IBS takes place in the bulk of the Si crystal. However, in another IBS study Nejim et~al.~\cite{nejim95} propose a % topotactic transformation that is likewise based on substitutional C, which replaces four of the eight Si atoms in the Si unit cell accompanied by the generation of four Si interstitials.