The substitutional fraction of Zn atoms which was diffused into single crystals was measured by using the proton-induced X-ray excitation technique. The diffusion times ranged from 0.25 to 1h at 425 to 650C. For several samples with diffusion depths ranging from 0.00075 to 0.0037mm (as determined using secondary ion mass spectrometry), it was found that the Zn impurity atoms resided almost entirely on lattice sites and that the substitutional fraction was equal to 0.9. There was no evidence of precipitation in the diffused layers. Only 1 to 10% of the Zn was electrically active. This was consistent with the existence of neutral VPZnInVP complexes.

W.N.Lennard, M.L.Swanson, D.Eger, A.J.Springthorpe, F.R.Shepherd: Journal of Electronic Materials, 1988, 17[1], 1-4