Effect of redeposition — An important consideration in existing mathematical model of sputtering process in focused ion beam milling

Microchannels with nano level accuracy have found their applications in almost all fields of research. In this paper, efforts have been made to generate sine wave and rectangular cross sections of microchannels using an existing mathematical model of depth of sputtering in focused ion beam (FIB) milling process. The existing mathematical model to calculate the depth of sputtering finds deviation from experimental data due to effect of redeposition, which has not been incorporated into it. A modified mathematical model, which incorporates the effect of redeposition via a ratio of redeposition to beam velocity, has been proposed in this paper. Normalized pixel spacing is another parameter, which has also been newly considered in modified mathematical model. Modified mathematical model has been simulated for sinusoidal and rectangular cross sectional profiles of microchannels and it has been proven more accurate than existing mathematical model through the comparison with experimental data of sinusoidal and rectangular geometry on Si material.