finished substoichiometric c in si section, started conversion mechanism section

diff --git a/bibdb/bibdb.bib b/bibdb/bibdb.bib
index ebcc267..076bf0e 100644 (file)
--- a/bibdb/bibdb.bib
+++ b/bibdb/bibdb.bib
@@ -935,6 +935,24 @@
   author =       "A. R. Bean and R. C. Newman",
 }
 
   author =       "A. R. Bean and R. C. Newman",
 }
 

+@Article{durand99,
+  author =       "F. Durand and J. Duby",
+  affiliation =  "EPM-Madylam, CNRS and INP Grenoble, France",
+  title =        "Carbon solubility in solid and liquid silicon—{A}
+                 review with reference to eutectic equilibrium",
+  journal =      "Journal of Phase Equilibria",
+  publisher =    "Springer New York",
+  ISSN =         "1054-9714",
+  keyword =      "Chemistry and Materials Science",
+  pages =        "61--63",
+  volume =       "20",
+  issue =        "1",
+  URL =          "http://dx.doi.org/10.1361/105497199770335956",
+  note =         "10.1361/105497199770335956",
+  year =         "1999",
+  notes =        "better c solubility limit in silicon",
+}
+

 @Article{watkins76,
   title =        "{EPR} Observation of the Isolated Interstitial Carbon
                  Atom in Silicon",
 @Article{watkins76,
   title =        "{EPR} Observation of the Isolated Interstitial Carbon
                  Atom in Silicon",


@@ -1142,6 +1160,26 @@
   notes =        "c diffusion due to si self-interstitials",
 }
 
   notes =        "c diffusion due to si self-interstitials",
 }
 

+@Article{fukami90,
+  author =       "Akira Fukami and Ken-ichi Shoji and Takahiro Nagano
+                 and Cary Y. Yang",
+  collaboration = "",
+  title =        "Characterization of SiGe/Si heterostructures formed by
+                 Ge[sup + ] and {C}[sup + ] implantation",
+  publisher =    "AIP",
+  year =         "1990",
+  journal =      "Applied Physics Letters",
+  volume =       "57",
+  number =       "22",
+  pages =        "2345--2347",
+  keywords =     "HETEROJUNCTIONS; ION IMPLANTATION; HETEROSTRUCTURES;
+                 FABRICATION; PN JUNCTIONS; LEAKAGE CURRENT; GERMANIUM
+                 SILICIDES; SILICON; ELECTRICAL PROPERTIES; SOLIDPHASE
+                 EPITAXY; CARBON IONS; GERMANIUM IONS",
+  URL =          "http://link.aip.org/link/?APL/57/2345/1",
+  doi =          "10.1063/1.103888",
+}
+

 @Article{strane93,
   author =       "J. W. Strane and H. J. Stein and S. R. Lee and B. L.
                  Doyle and S. T. Picraux and J. W. Mayer",
 @Article{strane93,
   author =       "J. W. Strane and H. J. Stein and S. R. Lee and B. L.
                  Doyle and S. T. Picraux and J. W. Mayer",


@@ -2557,7 +2595,28 @@
                  quasi-direct one",
 }
 
                  quasi-direct one",
 }
 

-@Conference{powell93,
+@Article{eberl92,
+  author =       "K. Eberl and S. S. Iyer and S. Zollner and J. C. Tsang
+                 and F. K. LeGoues",
+  collaboration = "",
+  title =        "Growth and strain compensation effects in the ternary
+                 Si[sub 1 - x - y]Ge[sub x]{C}[sub y] alloy system",
+  publisher =    "AIP",
+  year =         "1992",
+  journal =      "Applied Physics Letters",
+  volume =       "60",
+  number =       "24",
+  pages =        "3033--3035",
+  keywords =     "SILICON ALLOYS; GERMANIUM ALLOYS; CARBON ALLOYS;
+                 TERNARY ALLOYS; SEMICONDUCTOR ALLOYS; MOLECULAR BEAM
+                 EPITAXY; INTERNAL STRAINS; TEMPERATURE EFFECTS; CRYSTAL
+                 STRUCTURE; LATTICE PARAMETERS; XRAY DIFFRACTION; PHASE
+                 STUDIES",
+  URL =          "http://link.aip.org/link/?APL/60/3033/1",
+  doi =          "10.1063/1.106774",
+}
+
+@Article{powell93,

   author =       "A. R. Powell and K. Eberl and F. E. LeGoues and B. A.
                  Ek and S. S. Iyer",
   collaboration = "",
   author =       "A. R. Powell and K. Eberl and F. E. LeGoues and B. A.
                  Ek and S. S. Iyer",
   collaboration = "",


@@ -2579,6 +2638,93 @@
   notes =        "substitutional c in si by mbe",
 }
 
   notes =        "substitutional c in si by mbe",
 }
 

+@Article{powell93_2,
+  title =        "Si[sub 1-x-y]Ge[sub x]{C}[sub y] growth and properties
+                 of the ternary system",
+  journal =      "Journal of Crystal Growth",
+  volume =       "127",
+  number =       "1-4",
+  pages =        "425--429",
+  year =         "1993",
+  note =         "",
+  ISSN =         "0022-0248",
+  doi =          "DOI: 10.1016/0022-0248(93)90653-E",
+  URL =          "http://www.sciencedirect.com/science/article/B6TJ6-46J3RF2-8H/2/27fc231f28e4dc0a3b4770e5cf03257e",
+  author =       "A. R. Powell and K. Eberl and B. A. Ek and S. S.
+                 Iyer",
+}
+
+@Article{osten94,
+  author =       "H. J. Osten",
+  title =        "Modification of Growth Modes in Lattice-Mismatched
+                 Epitaxial Systems: Si/Ge",
+  journal =      "physica status solidi (a)",
+  volume =       "145",
+  number =       "2",
+  publisher =    "WILEY-VCH Verlag",
+  ISSN =         "1521-396X",
+  URL =          "http://dx.doi.org/10.1002/pssa.2211450203",
+  doi =          "10.1002/pssa.2211450203",
+  pages =        "235--245",
+  year =         "1994",
+}
+
+@Article{dietrich94,
+  title =        "Lattice distortion in a strain-compensated
+                 $Si_{1-x-y}$$Ge_{x}$${C}_{y}$ layer on silicon",
+  author =       "B. Dietrich and H. J. Osten and H. R{\"u}cker and M.
+                 Methfessel and P. Zaumseil",
+  journal =      "Phys. Rev. B",
+  volume =       "49",
+  number =       "24",
+  pages =        "17185--17190",
+  numpages =     "5",
+  year =         "1994",
+  month =        jun,
+  doi =          "10.1103/PhysRevB.49.17185",
+  publisher =    "American Physical Society",
+}
+
+@Article{osten94_2,
+  author =       "H. J. Osten and E. Bugiel and P. Zaumseil",
+  collaboration = "",
+  title =        "Growth of an inverse tetragonal distorted SiGe layer
+                 on Si(001) by adding small amounts of carbon",
+  publisher =    "AIP",
+  year =         "1994",
+  journal =      "Applied Physics Letters",
+  volume =       "64",
+  number =       "25",
+  pages =        "3440--3442",
+  keywords =     "SILICON ALLOYS; GERMANIUM ALLOYS; FILM GROWTH; CARBON
+                 ALLOYS; TERNARY ALLOYS; MOLECULAR BEAM EPITAXY; TEM;
+                 XRD; LATTICE PARAMETERS; EPITAXIAL LAYERS; TETRAGONAL
+                 LATTICES",
+  URL =          "http://link.aip.org/link/?APL/64/3440/1",
+  doi =          "10.1063/1.111235",
+  notes =        "inversely strained / distorted heterostructure",
+}
+
+@Article{iyer92,
+  author =       "S. S. Iyer and K. Eberl and M. S. Goorsky and F. K.
+                 LeGoues and J. C. Tsang and F. Cardone",
+  collaboration = "",
+  title =        "Synthesis of Si[sub 1 - y]{C}[sub y] alloys by
+                 molecular beam epitaxy",
+  publisher =    "AIP",
+  year =         "1992",
+  journal =      "Applied Physics Letters",
+  volume =       "60",
+  number =       "3",
+  pages =        "356--358",
+  keywords =     "SILICON ALLOYS; CARBON ALLOYS; BINARY ALLOYS;
+                 SEMICONDUCTOR ALLOYS; SUPERLATTICES; MOLECULAR BEAM
+                 EPITAXY; CHEMICAL COMPOSITION; TEMPERATURE EFFECTS;
+                 FILM GROWTH; MICROSTRUCTURE",
+  URL =          "http://link.aip.org/link/?APL/60/356/1",
+  doi =          "10.1063/1.106655",
+}
+

 @Article{osten99,
   author =       "H. J. Osten and J. Griesche and S. Scalese",
   collaboration = "",
 @Article{osten99,
   author =       "H. J. Osten and J. Griesche and S. Scalese",
   collaboration = "",


@@ -2682,6 +2828,48 @@
   notes =        "enhance of electron mobility in strained si",
 }
 
   notes =        "enhance of electron mobility in strained si",
 }
 

+@Article{kissinger94,
+  author =       "W. Kissinger and M. Weidner and H. J. Osten and M.
+                 Eichler",
+  collaboration = "",
+  title =        "Optical transitions in strained Si[sub 1 - y]{C}[sub
+                 y] layers on Si(001)",
+  publisher =    "AIP",
+  year =         "1994",
+  journal =      "Applied Physics Letters",
+  volume =       "65",
+  number =       "26",
+  pages =        "3356--3358",
+  keywords =     "SILICON CARBIDES; INTERNAL STRAINS; EPITAXIAL LAYERS;
+                 CHEMICAL COMPOSITION; ELLIPSOMETRY; REFLECTION
+                 SPECTROSCOPY; ELECTROOPTICAL EFFECTS; BAND STRUCTURE;
+                 ENERGY LEVELS; ENERGYLEVEL TRANSITIONS",
+  URL =          "http://link.aip.org/link/?APL/65/3356/1",
+  doi =          "10.1063/1.112390",
+  notes =        "strained si influence on optical properties",
+}
+
+@Article{osten96,
+  author =       "H. J. Osten and Myeongcheol Kim and K. Pressel and P.
+                 Zaumseil",
+  collaboration = "",
+  title =        "Substitutional versus interstitial carbon
+                 incorporation during pseudomorphic growth of Si[sub 1 -
+                 y]{C}[sub y] on Si(001)",
+  publisher =    "AIP",
+  year =         "1996",
+  journal =      "Journal of Applied Physics",
+  volume =       "80",
+  number =       "12",
+  pages =        "6711--6715",
+  keywords =     "SILICON CARBIDES; CRYSTAL DEFECTS; FILM GROWTH;
+                 MOLECULAR BEAM EPITAXY; INTERSTITIALS; SUBSTITUTION;
+                 XRD; STRAINS",
+  URL =          "http://link.aip.org/link/?JAP/80/6711/1",
+  doi =          "10.1063/1.363797",
+  notes =        "mbe substitutional vs interstitial c incorporation",
+}
+

 @Article{osten97,
   author =       "H. J. Osten and P. Gaworzewski",
   collaboration = "",
 @Article{osten97,
   author =       "H. J. Osten and P. Gaworzewski",
   collaboration = "",

diff --git a/posic/thesis/sic.tex b/posic/thesis/sic.tex
index 5fe0564..c10fe17 100644 (file)
--- a/posic/thesis/sic.tex
+++ b/posic/thesis/sic.tex
@@ -330,24 +330,53 @@ Due to the absence of dislocations in the implanted region interstitial C is ass
 
 % link to strain engineering
 However, there is great interest to incorporate C onto substitutional lattice sites, which results in a contraction of the Si lattice due to the smaller covalent radius of C compared to Si \cite{baker68}, causing tensile strain, which is applied to the Si lattice.
 
 % link to strain engineering
 However, there is great interest to incorporate C onto substitutional lattice sites, which results in a contraction of the Si lattice due to the smaller covalent radius of C compared to Si \cite{baker68}, causing tensile strain, which is applied to the Si lattice.

-Thus, substitutional C enables strain engineering of Si and Si/Si$_{1-x}$Ge$_x$ heterostructures \cite{yagi02,chang05,osten97}, which is used to increase charge carrier mobilities in Si as well as to adjust its band structure \cite{soref91,kasper91}.
+Thus, substitutional C enables strain engineering of Si and Si/Si$_{1-x}$Ge$_x$ heterostructures \cite{yagi02,chang05,kissinger94,osten97}, which is used to increase charge carrier mobilities in Si as well as to adjust its band structure \cite{soref91,kasper91}.

 % increase of C at substitutional sites
 Epitaxial layers with \unit[1.4]{at.\%} of substitutional C have been successfully synthesized in preamorphized Si$_{0.86}$Ge$_{0.14}$ layers, which were grown by CVD on Si substrates, using multiple-energy C implantation followed by solid-physe epitaxial regrowth at \unit[700]{$^{\circ}$C} \cite{strane93}.
 The tensile strain induced by the C atoms is found to compensates the compressive strain present due to the Ge atoms.
 Studies on the thermal stability of Si$_{1-y}$C$_y$/Si heterostructures formed in the same way and equal C concentrations showed a loss of substitutional C accompanied by strain relaxation for temperatures ranging from \unit[810-925]{$^{\circ}$C} and the formation of spherical 3C-SiC precipitates with diameters of \unit[2-4]{nm}, which are incoherent but aligned to the Si host \cite{strane94}.
 During the initial stages of precipitation C-rich clusters are assumed, which maintain coherency with the Si matrix and the associated biaxial strain.
 % increase of C at substitutional sites
 Epitaxial layers with \unit[1.4]{at.\%} of substitutional C have been successfully synthesized in preamorphized Si$_{0.86}$Ge$_{0.14}$ layers, which were grown by CVD on Si substrates, using multiple-energy C implantation followed by solid-physe epitaxial regrowth at \unit[700]{$^{\circ}$C} \cite{strane93}.
 The tensile strain induced by the C atoms is found to compensates the compressive strain present due to the Ge atoms.
 Studies on the thermal stability of Si$_{1-y}$C$_y$/Si heterostructures formed in the same way and equal C concentrations showed a loss of substitutional C accompanied by strain relaxation for temperatures ranging from \unit[810-925]{$^{\circ}$C} and the formation of spherical 3C-SiC precipitates with diameters of \unit[2-4]{nm}, which are incoherent but aligned to the Si host \cite{strane94}.
 During the initial stages of precipitation C-rich clusters are assumed, which maintain coherency with the Si matrix and the associated biaxial strain.

-Using this technique a metastable solubility limit was achieved, which corresponds to a C concentration exceeding the solid solubility limit at the Si melting point by nearly three orders of magnitude and, furthermore, a reduction of the defect denisty near the metastable solubility limit is assumed if the regrowth temperature is increased by a rapid thermal annealing process \cite{strane96}.
-By MBE ... \cite{powell93,osten99}
+Using this technique a metastable solubility limit was achieved, which corresponds to a C concentration exceeding the solid solubility limit at the Si melting point by nearly three orders of magnitude and, furthermore, a reduction of the defect denisty near the metastable solubility limit is assumed if the regrowth temperature is increased by rapid thermal annealing \cite{strane96}.
+Since high temperatures used in the solid-phase epitaxial regrowth method promotes SiC precipitation, other groups realized substitutional C incorporation for strained Si$_{1-y}$C$_y$/Si heterostructures \cite{iyer92,fischer95,powell93,osten96,osten99,laveant2002} or partially to fully strain-compensated (even inversely distorted \cite{osten94_2}) Si$_{1-x-y}$Ge$_x$C${_y}$ layers on Si \cite{eberl92,powell93_2,osten94,dietrich94} by \ac{MBE}.
+Investigations reveal a strong dependence of the growth temperature on the amount of substitutionally incorporated C, which is increased for decreasing temperature accompanied by deterioration of the crystal quality \cite{osten96,osten99}.
+While not being compatible to very-large-scale integration technology, C concentrations of \unit[2]{\%} and more have been realized \cite{laveant2002}.

 
 \section{Assumed silicon carbide conversion mechanisms}
 \label{section:assumed_prec}
 
 
 \section{Assumed silicon carbide conversion mechanisms}
 \label{section:assumed_prec}
 

-Although much progress has been made in 3C-SiC thin film growth in the above-mentioned growth methods during the last decades, there is still potential
-.. compatible to the established and highly developed technology based on silicon.
+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.

 
 

-Although tremendous progress has been achieved in the above-mentioned growth methods during the last decades, available wafer dimensions and crystal qualities are not yet statisfactory.
+\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 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.
+
+Coherency is lost once the increasing strain energy of the stretched SiC structure surpasses the interfacial energy of the incoherent 3C-SiC precipitate and the Si substrate.
+
+These two different mechanisms 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.
+
+However, in another IBS study Nejim et~al.\cite{nejim95} propose a topotactic transformation that is likewise based on the formation of substitutional C.
+
+The formation of substitutional C, however, is accompanied by Si self-interstitial atoms that previously occupied the lattice sites and a concurrent reduction of volume due to the lower lattice constant of SiC compared to Si.
+
+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
+
+more: taylor93, kitabatake contraction along 110, koegler03

 
 

-... \cite{lindner99_2} ...

 
 %   -> skorupa 3.2: c sub vs sic prec  
 
 
 %   -> skorupa 3.2: c sub vs sic prec