Enhanced nitrogen incorporation by pulsed laser annealing of GaNxAs1-x formed by N ion implantation

We demonstrate that pulsed laser annealing followed by rapid thermal annealing greatly enhances incorporation of substitutional N in N1-implanted GaAs. Films implanted to 1.8% N exhibit a fundamental band gap of 1.26 eV (a band gap reduction of 160 meV), corresponding to an N activation efficiency of 50%. The optical and crystalline quality of the synthesized film is comparable to GaNxAs1-x thin films of similar composition grown by epitaxial growth techniques. Compared to films produced by N1 implantation and rapid thermal annealing only, the introduction of pulsed laser annealing improves N incorporation by a factor of 5. Moreover, we find that the synthesized films are thermally stable up to an annealing temperature of 950 °C.