Two‐Dimensional Profile Simulation of Focused Ion‐Beam Milling of LSI

Abstract

Focused ion‐beam milling has recently been used for modifying and debugging LSIs, where precise depth control is required. In order to analyze the effects of scanning width and redeposition on hole depth, we have developed a two‐dimensional milling profile simulator, which takes redeposition into consideration. The results of the simulation are in good agreement with our experiments. It has been demonstrated that when the beam scanning width is less than the beam tail diameter, the milling depth declines due to dose deficiency. When the aspect ratio (depth/width) is high, the depth is less than proportional to the dose due to redeposition.