Atomically flat GaMnN by diffusion of Mn into GaN(000 over(1, ̄))

The interaction of Mn thin films on atomically flat GaN(000 over(1, ̄)) has been investigated by Scanning Tunneling Microscopy (STM) and Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). GaN surfaces prepared by repeated sputtering/annealing cycles show various reconstructions but essentially the 6×6 one. A high density of small islands (height 0.6 nm, diameter 5 nm) nucleates upon deposition of 0.3 ML Mn. Upon annealing at 575 C, these islands coalesce into larger islands (height 4 nm, diameter 50 nm) between which the GaN surface is visible. Atomically resolved STM images between the islands show the (3×3) reconstruction of GaN. Annealing the sample further to 675 C leads to the restoration of a bare GaN surface. ToF-SIMS reveals that Mn diffused into the bulk of the sample.