The non-thermal effects of illumination upon surface diffusion at high temperatures were measured (table 210). It was found that the activation energies and pre-exponential factors for the diffusion of Sb changed upon illumination with photons having energies that were greater than the substrate band-gap. These parameters decreased for n-type material, and increased for p-type material. Together with photoreflectance spectroscopic data, this suggested that motion of the surface quasi-Fermi level for minority carriers accounted for much of the effect by changing the charge states of surface vacancies. An additional adatom-vacancy complexing mechanism appeared to operate on p-type substrates.

R.Ditchfield, D.Llera-Rodríguez, E.G.Seebauer: Physical Review B, 2000, 62[20], 13710-20

Table 210

Arrhenius Parameters for Sb Diffusion on (111) Si Surfaces