Simulation of three-dimensional stop-ion and deposited energy distributions in amorphous chalcogenide resist film by Ga ion exposure

The Monte-Carlo (MC) simulation of three-dimensional (3D) stop-ion and deposited energy distributions in amorphous chalcogenide resist film by Ga⁺ ion beam exposure are presented. This paper is a part of the development of 3D MC Code suited for focused ion beam (FIB) lithography. For 3D MC simulations which are based on the simulation of individual energetic ions through their successive collisions with resist constituents, both the target depth (z-direction) and the lateral distance (x- and y-direction) are divided into discrete cubic pixels with 25×25×25 Å, nuclear scattering and stop-ion positions and ion-loss energies are summed up in these 3D pixels by ~10 ⁴ Ga⁺ ion trajectories, and then 3D ion concentration and deposited energy distribution profiles are obtained by an Ga⁺ ion beam exposure with proper shape and dose