Vacancy-related defect distributions in 11B-, 14N-, and 27Al-implanted 4H–SiC: Role of channeling

The defect distributions in 11B-, 14N-, and 27Al-implanted epitaxial 4H–SiC are studied using monoenergetic positron beams. At least three types of defects are needed to account for the Doppler broadening annihilation spectra and two of the defects are tentatively identified as VSi, and VSiVC. By comparing the defect profiles extracted from the annihilation spectra to the chemical profiles determined by secondary ion mass spectrometry, and to the primary defect profiles obtained from binary collision approximation simulations, it is concluded that the defects found at depths considerably deeper than the projected range of the implanted ions mainly originate from deeply channeled ions.