The complex mechanisms of ion-beam-induced deposition

We report the results of an investigation of ion-beam-induced deposition (IBID) mechanisms in terms of secondary atoms, secondary electrons, and primary ions. Comparison of the volume of a deposited box with that of the material deposited onto a nearby sidewall shows the significant contribution of secondary particles to IBID. In situ measurement of the Gal ion beam angular dependence of the deposition yield and of the sputtering yield shows the significant distinct behavior of deposition and sputtering, indicating that IBID cannot be explained solely in terms of sputtering (secondary atom emission). By varying the current and dwell time of a Ga(+) ion beam in spot mode, a doughnut-like structure with a hole or a central tip was obtained, indicating that primary ions probably also contribute to IBID.