SiC - Silicon Carbide

Impurities and defects

Impurities and defects

Solubility of impurities in SiC

Impurities       ceqmax Remarks Referens
N 2.6 x 1020 cm-3     2450° C, crystal growth;
nitrogen pressure 35 atm 		Scace & Slace (1965)
Be 7.0 x 1017 cm-3 1800° C, diffusion experiments Maslakovets et al. (1968)
Be 5.0 x 1019 cm-3 2300° C, diffusion experiments  
B 2.0 x 1019 cm-3 1800° C, epitaxial growth, (0001) face Tairov & Vodakov (1977)
B 1.5 x 1020 cm-3 2300° C, epitaxial growth, (0001) face  
B 4.0 x 1019 cm-3 1800° C, epitaxial growth, (0001) face  
B 2.5 x 1020 cm-3 2300° C, epitaxial growth, (0001) face  
Al 1.1 x 1021 cm-3 2300° C, epitaxial growth, (0001) face Tairov & Vodakov (1977)
Al 7.0 x 1020 cm-3 2300° C, epitaxial growth, (0001) face  
Ga 1.2 x 1019 cm-3 1800° C, epitaxial growth, (0001) face Tairov & Vodakov (1977)
Ga 1.2 x 1020 cm-3 2300° C, epitaxial growth, (0001) face  
Ga 2.8 x 1018 cm-3 1800° C, epitaxial growth, (0001) face  
Ga 7.0 x 1018 cm-3 2300° C, epitaxial growth, (0001) face  

Diffusion constants of impurities in 6H-SiC

Impurities       D0       Q Remarks Referens
N 4.6...8.7 x 10-4 cm-2/c 7.6...9.3 eV 2000...2550° C, pn-junction Kroko & Milnes (1966)
Be 32.0 cm-2/c 5.2 eV 1950...2250° C, pn-junction ,
probably substitutional diffusion 		Maslakovets et al. (1968)
Be 0.3 cm-2/c 3.1 eV 1700...2100° C, pn-junction ,
probably substitutional diffusion 		Maslakovets et al. (1968)
B 1.6 x 102 cm-2/c 5.6 eV 1800...2250° C, pn-junction Vodakov et al. (1966)
B 3.2 cm-2/c 5.1 eV 1600...2550° C, pn-junction Vodakov et al. (1974)
Al 1.8 cm-2/c 4.9 eV 1700...2000° C, pn-junction Chang et al. (1960)
Al 0.2 cm-2/c 4.9 eV 1800...2250° C, pn-junction Vodakov et al. (1966)
Al 8.0 cm-2/c 6.1 eV 1900...2300° C, pn-junction Mokhov et al. (1969)
Al 1.3 x 10-8 cm-2/c 2.4 eV 1350...1800° C, Ion implantation;
SIMS measurements 		Tajima et al. (1982)
Ga 0.17 cm-2/c 5.5 eV 2050...2300° C, pn-junction Vodakov et al. (1974)

Donors

Due to the existence of inequivalent lattice sites in silicon carbide (except for the 3C-SiC and 2H-SiC polytypes), there are several site-dependent energy levels for each donor or acceptor, respectively. Under most experimental conditions, however, one can only distinguish between energy levels assigned to impurity atoms at c-sites and energy levels caused by impurity atoms at h-sites. Impurity atoms at c-sites generally exhibit deeper levels than those at h-sites
Ionization energies of Shallow Donors   Remarks Referens
3C-SiC N 0.06-0.1 eV 300 K Lebedev (1999)
  N 0.0536 eV 6 K Lebedev (1999)
  N 0.0536(5) eV 6 K, photoluminescence Dean et al. (1977)
  N 0.0565 eV 4 K, photoluminescence Kuwabara et al. (1976)
4H-SiC N 0.059-0.102 eV
   Choyke and Pensl (1997)
See also Lebedev (1999)
  N 0.066 eV 4 K, h-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  N 0.124 eV 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  N 0.055(7) eV 77 K, photoluminescence Suzuki et al. (1977)
  Ti 0.13 eV
0.17 eV		   Lebedev (1999)
  Cr 0.15 -0.18 eV
0.74 eV		   Lebedev (1999)
6H-SiC N 0.085-0.125 eV   Choyke and Pensl (1997)
See also Lebedev (1999)
  N 0.095 eV 60...1000 K, nd = 5·1016 cm-3,
evaluation of Hall data; n(T) 		Hagen & Kapteyns (1970)
  N 0.100 eV 4 K, h-site,
luminescence of donor-acceptor pairs		 Ikeda et al. (1980)
  N 0.155 eV 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  P 0.085 eV
0.135 eV		   Choyke and Pensl (1997)
See also Lebedev (1999)
15R-SiC N 0.052 eV 60...1000 K, nd = 3·1016 cm-3,
evaluation of Hall data; n(T) 		Hagen & Kapteyns (1970)
  N 0.064 eV 4 K, h-site,
luminescence of donor-acceptor pairs		 Ikeda et al. (1980)
  N 0.112 eV 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)

Acceptors

Due to the existence of inequivalent lattice sites in silicon carbide (except for the 3C-SiC and 2H-SiC polytypes), there are several site-dependent energy levels for each donor or acceptor, respectively. Under most experimental conditions, however, one can only distinguish between energy levels assigned to impurity atoms at c-sites and energy levels caused by impurity atoms at h-sites. Impurity atoms at c-sites generally exhibit deeper levels than those at h-sites
Ionization energies of Shallow Acceptors   Remarks Referens
3C-SiC Al 0.26 eV   Lebedev (1999)
  Al 0.216 eV 1.8 K,
luminescence of donor-acceptor pairs 		Choyke & Patric (1970)
  Al 0.260 eV 77 K, photoluminescence Zanmarchi (1968)
  Al 0.254 eV 4 K,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Ga 0.344 eV   Kuwabara and Yamada (1975)
  Ga 0.343 eV 4 K, photoluminescence Kuwabara et al. (1976)
  B 0.735 eV 4 K, photoluminescence Kuwabara & Yamada (1975)
4H-SiC Al 0.19 eV   Choyke and Pensl (1997)
See also Lebedev (1999)
  Al 0.191 eV 4 K,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Ga 0.267 eV 4 K,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  B 0.647 eV 77 K, photoluminescence Ikeda et al. (1980)
6H-SiC Al 0.239 eV   Ikeda et al. (1980) )
See also Lebedev (1999)
  Al 0.239 eV 4 K, h-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Al 0.249 eV 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Al 0.280 eV 160 K, DLTS Anikin et al. (1985)
  Al 0.315 eV 300...1300 K, na = 5·1018 cm-3,
evaluation of Hall data; p(T) 		Van Daal al. (1963)
  Al 0.220 eV 300...1300 K, na = 2·1019 cm-3,
evaluation of Hall data; p(T) 		Van Daal al. (1963)
  Ga 0.317 eV 4 K, h-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Ga 0.333 eV 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Be 0.320 eV 280...420 K, photoluminescence Kalnin et al. (1977)
  Be 0.420 eV
0.600 eV		 300...1000 K, photoluminescence Maslakovets et al. (1968)
  B 0.27 eV
0.31-0.38 eV		   Evwaraye et al. (1997)
  B 0.698 eV 77 K, h-site,
photoluminescence 		Ikeda et al. (1980)
  B 0.723 eV 77 K, c-site,
photoluminescence 		Ikeda et al. (1980)
15R-SiC Al 0.206 eV
0.221 eV		 4 K, h-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Al 0.223 eV
0.230 eV
0.236 eV		 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  B 0.666 eV 77 K, h-site,
photoluminescence 		Ikeda et al. (1980)
  B 0.700 eV 77 K, c-site,
photoluminescence 		Ikeda et al. (1980)
  Ga 0.282 eV
0.300 eV		 4 K, h-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
  Ga 0.305 eV
0.311 eV
0.320 eV		 4 K, c-site,
luminescence of donor-acceptor pairs 		Ikeda et al. (1980)
3C-SiC. The diagram of main impurities in 3C-SiC.
Dean et al. (1977), Dombrowski et al. (1994), Ikeda et al. (1980), Kuwabara et al. (1976), Kuwabara and Yamada (1975), Lebedev (1999)
4H-SiC. The diagram of main impurities in 4H-SiC.
Achtziger & Witthuhn (1997), Dalibor et al. (1997), Dombrowski et al. (1994), Evwaraye et al. (1996), Ikeda et al. (1980), Kuznetsov & Zubrilov (1995), Lebedev & Poletaev (1996), Lebedev (1999).
6H-SiC. The diagram of main impurities in 6H-SiC.
Anikin et al. (1991), Evwaraye et al. (1994), Evwaraye et al. (1996), Evwaraye et al. (1997), Hobgood et al. (1995), Kuznetsov et al. (1994), Kuznetsov & Edmond (1997), Lebedev & Davydov (1997), Mitchel et al. (1997), Troffer et al. (1997), Lebedev (1999)