%0 Journal Article
%A Catarino, N.
%A Nogales Díaz, Emilio
%A Franco, N.
%A Darakchieva, V.
%A Miranda, S.M.C.
%A Méndez Martín, Bianchi
%A Alves, E.
%A Marques, J.F.
%A Lorenz, K.
%T Enhanced dynamic annealing and optical activation of Eu implanted a-plane GaN
%D 2012
%@ 0295-5075
%U https://hdl.handle.net/20.500.14352/44054
%X 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 ^5Do -> ^7F_2transition in the Eu_3+ 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.
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