slightly more on sic homoepitaxy using gsmbe

diff --git a/posic/thesis/sic.tex b/posic/thesis/sic.tex
index 5ba9554..6cdd825 100644 (file)
--- a/posic/thesis/sic.tex
+++ b/posic/thesis/sic.tex
@@ -194,9 +194,13 @@ Using alternating supply of the gas beams Si$_2$H$_6$ and C$_2$H$_2$ in GSMBE, 3
 On \hkl(000-1) substrates twinned \hkl(-1-1-1) oriented 3C-SiC domains are observed, which suggest a nucleation driven rather than step-flow growth mechanism.
 On \hkl(0-11-4) substrates, however, single crystalline \hkl(001) oriented 3C-SiC grows with the c axes of substrate and film being equal.
 The beneficial epitaxial relation of substrate and film limits the structural difference between the two polytypes in two out of six layers with respect to the stacking sequence along the c axis.
-Homoepitaxial growth of 3C-SiC by GSMBE was realized for the first time by atomic layer epitaxy (ALE) utilizing the change in the surface superstructure, which gives atomic level control in the growth process \cite{fuyuki89}.
-in more detail ... \cite{yoshinobu90}.
-3C on 3C homoepitaxy by ALE \cite{fuyuki89,fuyuki93,hara93}
+Homoepitaxial growth of 3C-SiC by GSMBE was realized for the first time by atomic layer epitaxy (ALE) utilizing the periodical change in the surface superstructure by the alternating supply of the source gases, which determines the growth rate giving atomic level control in the growth process \cite{fuyuki89}.
+The cleaned substrate surface shows a $(1\times 1)$ pattern at \unit[1000]{$^{\circ}$C}, which turns into a $(3\times 2)$ pattern when Si$_2$H$_6$ is introduced and it is maintained after the supply is stopped.
+A more detailed investigation showed the formation of a preceeding $(2\times 1)$ pattern within the exposure to the Si containing gas \cite{yoshinobu90}.
+The $(3\times 2)$ superstructure contains approximately 1.7 monolayers of Si atoms.
+The insertion of C$_2$H$_6$ leads to a reconstruction of the surface into the initial $(1\times 1)$ pattern and the formation of crystalline 3C-SiC with a smooth and mirror-like surface after an appropriate number of cycles.
+The growth rate ... higher, due to physically adsorbed Si, which depends on Si supply ...
+Not really ALE ... 1.7 monolayers per cycle ... now real ALE \cite{fuyuki93,hara93}
 6H on 6H ... \cite{tanaka94}
 Problem of gas source ... strong adsorption and incorporation of atomic decomposited hydrogen of the gas phase reactants at low temperatures.
 Growth rate lower than desorption rate of hydrogen ...