Enhanced dynamic annealing and optical activation of Eu implanted a-plane GaN
2012 (English)In: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 97, no 6, 68004- p.Article in journal (Refereed) Published
The implantation damage build-up and optical activation of a-plane and c-plane GaN epitaxial films were compared upon 300 keV Eu implantation at room temperature. The implantation defects cause an expansion of the lattice normal to the surface, i.e. along the a-direction in a-plane and along the c-direction in c-plane GaN. The defect profile is bimodal with a pronounced surface damage peak and a second damage peak deeper in the bulk of the samples in both cases. For both surface orientations, the bulk damage saturates for high fluences. Interestingly, the saturation level for a-plane GaN is nearly three times lower than that for c-plane material suggesting very efficient dynamic annealing and strong resistance to radiation. a-plane GaN also shows superior damage recovery during post-implant annealing compared to c-plane GaN. For the lowest fluence, damage in a-plane GaN was fully removed and strong Eu-related red luminescence is observed. Although some residual damage remained after annealing for higher fluences as well as in all c-plane samples, optical activation was achieved in all samples revealing the red emission lines due to the 5D0→ 7F2transition in the Eu3+ ion. The presented results demonstrate a great promise for the use of ion beam processing for a-plane GaN based electronic devices as well as for the development of radiation tolerant electronics.
Place, publisher, year, edition, pages
2012. Vol. 97, no 6, 68004- p.
III-V semiconductors, Doping and impurity implantation, Cathodoluminescence, ionoluminescence
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-91706DOI: 10.1209/0295-5075/97/68004OAI: oai:DiVA.org:liu-91706DiVA: diva2:618732