Phosphorus-related donors in 6H-SiC generated by ion implantation

Aluminum-doped GH-SiC epilayers were implanted with phosphorus and subsequently annealed in a temperature range from 1400 to 1700 degrees C. The annealing behavior of implanted phosphorus atoms was studied by the Hall effect, admittance spectroscopy, and photoluminescence. Phosphorus acts as a shallow donor. Two ionization energies of (80+/-5) meV and (110+/-5) meV are determined, which are assigned to phosphorus atoms residing at hexagonal and cubic lattice sites, respectively. Assuming first-order kinetics, the annealing process results in an activation energy of the phosphorus donors of 2.5 eV. A set of four lines at a wavelength of about 420/421 nm is observed in the low temperature photoluminescence spectra; the intensity of these lines increases in parallel with the electrical activation of phosphorus donors by raising the annealing temperature. It is proposed that these lines are phosphorus-related. (C) 1996 American Institute of Physics.