Variations of milling parameters and their effect on the volumetric sputtering yield of Silicon with the use of a plasma focused ion beam

Abstract

Volumetric sputtering is a technique used to polish the surface of materials at the atomic level used in the production of semi-conductors and nanotechnology. This study examined the effects of varying milling parameters, specifically voltage and current, on the volumetric sputtering yield of silicon using a plasma focused ion beam with argon gas. The experimental process used a Helios 5 Hydra DualBeam Scanning Electron Microscope Plasma Focused Ion Beam (SEM PFIB) to mill silicon surfaces with various voltage-current combinations. Milled depths were analysed in ImageJ, and volumetric sputtering yields were further calculated. The results demonstrate a statistically significant difference between the effects of voltage and current on the volumetric sputtering yield (ANOVA p = 0.02). Current was identified as a significant factor (p = 0.008), while voltage alone did not show statistical significance (p = 0.395). Accelerating voltages of 12 kV and 30 kV demonstrated the most stable and efficient sputtering processes. The results concluded that the inverse proportionality, \(\displaystyle Y_s = \frac{V_{\mathrm{removed}}}{q}\), was present between volumetric sputtering yield and charge, through volume removed, with a significant correlation between their natural logarithms (p = 0.003).