The diffusion coefficients and activation energy for Mn diffusion in ion-implanted and layered epitaxial structures of Ga1−xMnxAs/GaAs were deduced from quantitative time-of-flight secondary ion mass spectrometry data. The samples were annealed between the growth temperature (as low as 200C) and about 400C. Quantitative diffusion information was obtained by calibrating the Mn concentration to ion-implanted standards, and the depth scale to profilometry measurements. The depth-profiles obtained for ion-implanted Mn in GaAs at a dose of 1.35 x 1015/cm2 revealed an increased Mn concentration within the top 5nm of the sample, but otherwise revealed no significant differences in the implantation shape after annealing at up to 350C. Following an implantation dose of 8.1 x 1015/cm2, diffusion was initiated after annealing at 300C; with more significant diffusion at higher temperatures. An analysis of annealed epitaxial films of higher concentration (Ga0.89Mn0.11As) revealed diffusion at 200 to 400C, and an activation energy of 0.67eV was calculated by fitting the profiles to an error function.

Diffusion of Mn in GaAs Studied by Quantitative Time-of-Flight Secondary Ion Mass Spectrometry. R.E.Goacher, S.Hegde, H.Luo, J.A.Gardella: Journal of Applied Physics, 2009, 106[4], 044302