3-D SRIM simulation of focused ion beam sputtering with an application-oriented incident beam model

Ion beam sputter etching has been widely used in material surface modification and transmission electron microscope (TEM) sample preparation. Due to the complexity of the ion beam etching process, the quantitative simulation of ion beam sputtering is necessary to guarantee precision in surface treatment and sculpting under different energies and beam currents. In this paper, an application-oriented incident ion beam model was first built with aberrations and Coulomb repulsion forces being considered from the Ga ion source to the sample. The sputtering process of this model on the sample was then analyzed and simulated with an improved stopping and range of ions in metter (SRIM) program. The sputtering performance of this model, the point-like incident beam and the typical Gaussian incident beam was given in the end. Results show that the penetration depth of Ga ions having 30 keV energy in silicon is 28 nm and the radial range is 29.6 nm with 50 pA beam current. The application-oriented model has been verified by our focused ion beam-scanning electron microscopy (FIB-SEM) milling experiment and it will be a potential thermal source in simulating the process of FIB bombarding organic samples.