Simulation of focused ion beam milling

The computer program COMPOSITE ( Co mplete M odeling Program of Si licon Te chnology) is a two dimensional process simulator which containts a module for ion beam etching using the well-known string algorithm. This program was modified for focuses ion beam milling, particularly the beam was confined in one direction and the ion beam was given a Gaussian intensity distribution. The program was applied to problems occuring in X-ray mask repair whereby points of emphasis were the shape of the ion beam and redeposition of sputtered target material.