A photoluminescence study was made of the interdiffusion of P in the In0.66Ga0.33As/In0.66Ga0.33As0.7P0.3 system at temperatures ranging from 950 to 600C. It was shown that the diffusion was Fickian, with no dependence of the diffusion coefficient upon the substrate dopant-type or etch-pit density. In the case of Sn- or S-doped substrates, the diffusion could be described by:

D(cm2/s) = 23 exp[-3.7(eV)/kT]

at temperatures greater than 675C. This activation energy was the same as that deduced for group-III interdiffusion in Ga0.8In0.2As/GaAs. At lower temperatures, diffusivity in the present system could be described by:

D(cm2/s) = 5 x 10-10 exp[-1.7(eV)/kT]

W.P.Gillin, S.S.Rao, I.V.Bradley, K.P.Homewood, A.D.Smith, A.T.R.Briggs: Applied Physics Letters, 1993, 63[6], 797-9