\end{figure}
SiC was first discovered by Henri Moissan in 1893 when he observed brilliant sparkling crystals while examining rock samples from a meteor crater in Arizona.
He mistakenly identified these crystals as diamond.
-Although they might have been considered \glqq diamonds from space\grqq{} Moissan identified them as SiC in 1904~\cite{moissan04}.
+Although they might have been considered \glqq diamonds from space\grqq{}, Moissan identified them as SiC in 1904~\cite{moissan04}.
In mineralogy SiC is still referred to as moissanite in honor of its discoverer.
It is extremely rare and almost impossible to find in nature.
SiC is a mainly covalent material in which both, Si and C atoms are sp$^3$ hybridized.
Each of the four sp$^3$ hybridized orbitals of a Si atom overlaps with one of the four sp$^3$ hybridized orbitals of the four surrounding C atoms and vice versa.
-This results in fourfold coordinated mostly covalent $\sigma$ bonds of equal length and strength for each atom with its neighbors.
+This results in fourfold coordinated, mostly covalent $\sigma$ bonds of equal length and strength for each atom with its neighbors.
Although the local order of Si and C next neighbor atoms characterized by the tetrahedral bonding is the same, more than 250 different types of structures called polytypes of SiC exist~\cite{fischer90}.
The polytypes differ in the one-dimensional stacking sequence of identical, close-packed SiC bilayers.
Each SiC bilayer can be situated in one of three possible positions (abbreviated a, b or c) with respect to the lattice while maintaining the tetrahedral bonding scheme of the crystal.
% todo add more refs + check all values!
Different polytypes of SiC exhibit different properties.
Some of the key properties are listed in Table~\ref{table:sic:properties} and compared to other technologically relevant semiconductor materials.
-Despite the lower charge carrier mobilities for low electric fields SiC outperforms Si concerning all other properties.
+Despite the lower charge carrier mobilities for low electric fields, SiC outperforms Si concerning all other properties.
The wide band gap, large breakdown field and high saturation drift velocity make SiC an ideal candidate for high-temperature, high-power and high-frequency electronic devices exhibiting high efficiency~\cite{wesch96,morkoc94,casady96,capano97,pensl93,park98,edgar92}.
-In addition the high thermal conductivity enables the implementation of small-sized electronic devices enduring increased power densities.
+In addition, the high thermal conductivity enables the implementation of small-sized electronic devices enduring increased power densities.
Its formidable mechanical stability, heat resistance, radiation hardness and low neutron capture cross section allow operation in harsh and radiation-hard environments~\cite{capano97}.
In addition to high-temperature operations, the wide band gap also allows the use of SiC in optoelectronic devices.
These devices include ultraviolet (UV) detectors~\cite{brown93,yan04}, high power radio frequency (RF) amplifiers, rectifiers and switching transistors~\cite{pribble02,baliga96,weitzel96,zhu08,bhatnagar92,bhatnagar93,ryu01} as well as microelectromechanical system (MEMS) applications~\cite{sarro00}.
For UV detectors the wide band gap is useful for realizing low photodiode dark currents as well as sensors that are blind to undesired near-infrared wavelengths produced by heat and solar radiation.
These photodiodes serve as excellent sensors applicable in the monitoring and control of turbine engine combustion.
-The low dark currents enable the use in X-ray, heavy ion and neutron detection in nuclear reactor monitoring and enhanced scientific studies of high-energy particle collisions as well as cosmic radiation.
+The low dark currents enable the use in x-ray, heavy ion and neutron detection in nuclear reactor monitoring and enhanced scientific studies of high-energy particle collisions as well as cosmic radiation.
The low neutron capture cross section and radiation hardness favors its use in detector applications.
The high breakdown field and carrier saturation velocity coupled with the high thermal conductivity allow SiC RF transistors to handle much higher power densities and frequencies in stable operation at high temperatures.
Smaller transistor sizes and less cooling requirements lead to a reduced overall size and cost of these systems.
For instance, SiC based solid state transmitters hold great promise for High Definition Television (HDTV) broadcast stations~\cite{temcamani01,pribble02} abandoning the reliance on tube-based technology for high-power transmitters significantly reducing the size of such transmitters and long-term maintenance costs.
The high breakdown field of SiC compared to Si allows the blocking voltage region of a device to be designed roughly 10 times thinner and 10 times heavier doped, resulting in a decrease of the blocking region resistance by a factor of 100 and a much faster switching behavior.
Thus, rectifier diodes and switching transistors with higher switching frequencies and much greater efficiencies can be realized and exploited in highly efficient power converters.
-Therefor, SiC constitutes a promising candidate to become the key technology towards an extensive development and use of regenerative energies and electromobility.
+Therefore, SiC constitutes a promising candidate to become the key technology towards an extensive development and use of regenerative energies and electromobility.
Beside the mentioned electrical capabilities the mechanical stability, which is almost as hard as diamond, and chemical inertness almost suggest SiC to be used in MEMS designs.
Among the different polytypes of SiC, the cubic phase shows a high electron mobility and the highest break down field as well as saturation drift velocity~\cite{neudeck95,wesch96}.
In contrast to its hexagonal counterparts 3C-SiC exhibits isotropic mechanical and electronic properties.
Additionally the smaller band gap is expected to be favorable concerning the interface state density in MOSFET devices fabricated on 3C-SiC~\cite{pensl00}.
-Thus the cubic phase is most effective for highly efficient high-performance electronic devices.
+Thus, the cubic phase is most effective for highly efficient high-performance electronic devices.
\begin{figure}[t]
\begin{center}
\includegraphics[width=0.35\columnwidth]{sic_unit_cell.eps}
APB defects, which constitute the primary residual defects in thick layers, are formed near surface terraces that differ in a single-atom-height step resulting in domains of SiC separated by a boundary, which consists of either Si-Si or C-C bonds due to missing or disturbed sublattice information~\cite{desjardins96,kitabatake97}.
However, the number of such defects can be reduced by off-axis growth on a Si \hkl(0 0 1) substrate miscut towards \hkl[1 1 0] by \unit[2]{$^{\circ}$}-\unit[4]{$^{\circ}$}~\cite{shibahara86,powell87_2}.
This results in the thermodynamically favored growth of a single phase due to the uni-directional contraction of Si-C-Si bond chains perpendicular to the terrace steps edges during carbonization and the fast growth parallel to the terrace edges during growth under Si rich conditions~\cite{kitabatake97}.
+% more up2date paper
+A reduction of the SF in addition to the APB defects was recently achieved by growing 3C-SiC on undulant Si~\cite{nagasawa06}, i.e.\ a Si \hkl(0 0 1) substrate covered with continuous slopes oriented in the \hkl[1 1 0] and \hkl[-1 -1 0] directions.
+In this way, APB defects are eliminated by a mechanism similar to that in the off-axis growth process while, at the same time, SFs are aligned in the \hkl(1 1 1) or \hkl(-1 -1 1) planes and, thus, terminate as they connect with each other during the growth process.
+%
By MBE, lower process temperatures than these typically employed in CVD have been realized~\cite{hatayama95,henke95,fuyuki97,takaoka98}, which is essential for limiting thermal stresses and to avoid resulting substrate bending, a key issue in obtaining large area 3C-SiC surfaces.
In summary, the almost universal use of Si has allowed significant progress in the understanding of heteroepitaxial growth of SiC on Si.
However, mismatches in the thermal expansion coefficient and the lattice parameter cause a considerably high concentration of various defects, which is responsible for structural and electrical qualities that are not yet satisfactory.
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.
+Therefor, 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}.
The implantation temperature constitutes the most critical parameter, which is responsible for the structure after implantation and, thus, the starting point for subsequent annealing steps.
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