STRUCTURAL DEFECTS AND MICROSTRAIN IN GAN INDUCED BY MG ION-IMPLANTATION

The optical and structural characteristics of GaN films implanted with Mg and Be ions, grown by low-pressure metalorganic chemical vapor dep osition were studied. The low temperature (20 K) photoluminescence (PL ) spectra of annealed Mg implanted GaN show a 356 nm near band edge em ission, a 378 nm donor-acceptor (D-A) transition with phonon replicas, and a 528 nm green band deep level emission. The origin of the 528 nm green band emission and the 378 nm D-A emission might be attributed, respectively, to the Mg implantation induced clustering defect and the vacancy defect in GaN film. Observations of in-plane and out-of-plane x-ray diffraction spectra for as-grown undoped, Mg implanted and rapi d thermal annealed GaN suggest that ion implantation induced anisotrop ic strain may be responsible for the observed PL emission characterist ics. (C) 1998 American Institute of Physics. [S0021-8979(98)02711-X].