PHOSPHORUS-RELATED DONORS IN 6H-SIC GENERATED BY ION-IMPLANTATION

Aluminum-doped GH-SiC epilayers were implanted with phosphorus and sub sequently annealed in a temperature range from 1400 to 1700 degrees C. The annealing behavior of implanted phosphorus atoms was studied by t he Hall effect, admittance spectroscopy, and photoluminescence. Phosph orus acts as a shallow donor. Two ionization energies of (80+/-5) meV and (110+/-5) meV are determined, which are assigned to phosphorus ato ms residing at hexagonal and cubic lattice sites, respectively. Assumi ng first-order kinetics, the annealing process results in an activatio n 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 phot oluminescence spectra; the intensity of these lines increases in paral lel 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.