Pulsed excimer laser annealing of Mg-doped cubic GaN

A KrF (248 nm) excimer laser with a 38 ns pulse width was used to study pulsed laser annealing (PLA) on Mg-doped cubic GaN alms. The laser-induced changes were monitored by photoluminescence (PL) measurement. It indicated that deep levels in as-grown cubic GaN : Mg films were neutralized by H and PLA treatment could break Mg-H-N complex. The evolution of emissions around 426 and 468 nm with different PLA conditions reflected the different activation of the involved deep levels. Rapid thermal annealing (RTA) in N-2 atmosphere reverts the luminescence of laser annealed samples to that of the pre-annealing state. The reason is that most H atoms still remained in the epilayers after PLA due to the short duration of the pulses and reoccupied the original locations during RTA. (C) 2000 Elsevier Science B.V. All rights reserved. PACS: 61.72.Vv; 61.72.Cc; 18.55. -m.