NOVEL BEAM EFFECT - MASS-TRANSPORT DUE TO THE LATERAL COMPONENT OF THE ION MOMENTUM

A new effect in ion beam-solid interaction is described, namely mass t ransport in the bombarded solid due to lateral momentum transfer from the ions. It manifests itself, after high energy (several MeV) ion imp lantation at low temperature through a contact mask, as a surface depr ession at one end, and an elevated surface at the other end of the mas ked region. It is only evident for off-normal implantations, and then the depressed surface is always on the windward side of the mask and t he elevated surface region is always on the downwind side, and it incr eases superlinearly with ion energy. Electronic stopping effects play a major role not only for the momentum transfer but also for the plast ic deformation of the solid.