The first measurements of N diffusion in this material were reported (figure 16). Films with a buried N-doping layer were grown by means of molecular beam epitaxy and diffusion-annealing at 808 to 880C in an As-rich ambient. The N distributions which were revealed by secondary-ion mass spectroscopy indicated a marked non-Gaussian broadening of the as-grown peak. Computer modelling yielded strong evidence for the occurrence of a kick-out diffusion mechanism which involved interstitial-N and substitutional-N exchange that was assisted by As interstitials. It was thereby deduced that the As-interstitial related diffusion of As could be described by:

D (cm2/s) = 3 x 10-2 exp[-3.6(eV)/kT]

A comparison with existing As tracer-diffusivities indicated that interstitial As made a substantial contribution to As diffusion in this material.

Diffusion of Nitrogen from a Buried Doping Layer in Gallium Arsenide G.Bösker, N.A.Stolwijk, J.V.Thordson, U.Södervall, T.G.Andersson: Physical Review Letters, 1998, 81[16], 3443-6

Figure 17

Effective As-Sb Interdiffusivity in GaAs