FOCUSED-ION-BEAM-INDUCED TUNGSTEN DEPOSITION - THEORY AND EXPERIMENT

A time-dependent model for focused-ion-beam-induced metal deposition is presented which describes the competition between gas adsorption and ion-assisted ps removal, and the competition between metal deposition and sputtering. The model contains all major experimental variables such as current density, focus size, scan speed and frame time, and differentiates between the contribution of the beam centre and that of the beam wings. The scanning strategy of the beam during deposition is explicitly taken into account. The deposition Tate has been measured as a function of the major experimental variables. The model has been fitted to the data and is found to describe the various dependences satisfactorily.