The diffusion of N was studied in films, grown by molecular beam epitaxy, which contained a buried N doping layer with a maximum concentration of about 1019/cm3. The as-grown films were annealed at 724C to 922C in an As-rich ambient, and then analyzed by secondary ion mass spectrometry. A remarkably fast non-Gaussian broadening of the as-grown N distribution was observed. Evaluation of the profile shape provided strong evidence for a kick-out diffusion mechanism on the As sub-lattice; involving not only interstitial and substitutional N, but also interstitial As as a native point defect. Fitting the data on this basis yielded the diffusion coefficient of N as a function of temperature. It obeyed an equation of the form:

D (cm2/s) = 6.5 x 10-3 exp[-2.27(eV)/kT]

Diffusion of Nitrogen in Gallium Arsenide. N.A.Stolwijk, G.Bösker, T.G.Andersson, U.Södervall: Physica B, 2003, 340-342, 367-70

Figure 4

Diffusivity of S in GaAs