Sputtering

Sputtering is a process where atoms are ejected from a solid target material when it is bombarded by energetic particles. This process can lead, during prolonged ion or plasma bombardment of a material, to significant erosion. Sometimes sputtering is seen as a side effect that negatively affects the performance of materials, for example, in the erosion produced in Hall-effect plasma thrusters for spatial applications, or in the degradation of the confinement material for future nuclear fusion reactors. In other cases sputtering is used as a means to analyze the composition of a material, as it is the case of the Secondary Ion Mass Spectrometry. In the semiconductor industry sputtering is used to deposit thin films or for anisotropic etching and surface polishing.

In relation with these last practical applications of sputtering we carried out classical molecular dynamics simulations of the erosion of crystal and amorphous silicon films by argon ions. We demonstrated that sputtering depends on the implanted dose and the particular atomic structure of the target surface. We are also interested in the study of the silicon surface erosion produced by the impact of molecular ions, as well as in the dependence of sputtering on ion energy and impact angle in ceramic materials to be used in plasma thrusters.

Erosion of a silicon target surface by the implantation of B₁₈ molecular ions up to a dose of 10¹⁵ ions/cm².