Experiments were performed which were aimed at understanding the phenomena that deformed solid surfaces during irradiation with 24MeV heavy ions. These phenomena were density changes, anisotropic growth (thinning of a solid along the normal to the surface plus growth in the surface plane without density change) and lateral mass transport. Lateral mass transport occurred only if the ion beam was not perpendicular to the surface. It involved displacement of some of the implanted material along the surface, in the direction of the component of the ion velocity parallel to the surface. This resulted in the creation of a ditch and dyke at opposite edges of the irradiated zone. The contribution of lateral mass transport to surface deformation was deduced, and was studied as a function of ion fluence, flux, and species. Auger analysis of the surface eliminated sputtering and surface diffusion as being causes of the ditch and dyke structures.

M.Chicoine, S.Roorda, L.Cliche, R.A.Masut: Physical Review B, 1997, 56[3], 1551-60