Silicon carbide doped with gallium

Abstract

Silicon carbide (SiC) films doped with gallium are obtained during the process of epitaxial growth using the sublimation variant “sandwich method” or diffusion. It is determined by neutron activation analysis that the gallium solubility in SiC in the temperature range 1800 to 2400 °C does not exceed 1.2 × 1019 cm−3 at growth on the 〈0001〉 plane of substrate, but is lower at growth on the 〈0001〉 plane and in the mentioned temperature range the solubility changes from 2 × 1018 to 7 × 1018 cm−3. Data obtained correlate with the hole concentration value in these films determined from the analysis of the temperature dependence of Hall‐effect. The thermal activation energy of gallium in SiC defined from the electroconductivity is equal to 0.29 eV. Low‐temperature photoluminescence is investigated of SiC samples doped with gallium and nitrogen with n‐ and p‐type conductivity. The absorption spectra are given of grown crystals stimulated by optical transitions between gallium levels and valence band. It is shown that the parameters of the gallium diffusion in SiC excepting the accessible surface concentration are close to the parameters of aluminium diffusion. The surface concentration of gallium does not exceed 7 × 1017 cm−3 at the diffusion.

Deep Level Defects in Silicon Carbide

“…Gallium is another acceptor impurity in silicon carbide, but with a lower solubility than Al (~1.2-10 19 cnT 3 ) 53 ' 21 and a higher ionization energy [£ v +0.29eV (6H) and £ v +0.3eV {AH)] 53 ' 54 , which is commonly not used for fabrication of p-n structures. Some authors have observed two acceptor levels (E v +0.31 and E v +0.37 eV) related to Ga in 6H-S1C 5S .…”

Radiation Resistance of SiC and Nuclear-Radiation Detectors Based on SiC Films

“…Irradiation of other SiC polytypes gave rise to luminescence with similar properties [52]. Since this luminescence emerged as a result of irradiation or implantation of SiC with various ions, it was assumed that a center acting as the activator of luminescence had either a pure defect-related structure or was a complex which consisted of an intrinsic defect and an atom of a background impurity [58][59][60]. Choyke [61] detected excitons bound to deep-level centers in SiC.…”

Anti-site pair in SiC: a model of the DI center

“…the D I defect is very stable. The D I center was observed in all polytypes after various kinds of irradiation [1,[3][4][5][6], and was also observed in as-grown material after quenching from growth temperature and in epitaxial layers grown by chemical vapor deposition (CVD) [7][8][9][10] or molecular beam epitaxy (MBE) [11]. The photon energy of the zero-phonon luminescence is 0.35-0:45 eV below the excitonic gap independent of the polytype.…”