Dopant profile modeling by rare event enhanced domain-following molecular dynamics

Abstract

A computer-implemented molecular dynamics-based process simulates a distribution of ions implanted in a semiconductor substrate. The properties of the semiconductor substrate and ion dose to be simulated are first initialized, including an initial set of splitting depths that contain an equal number of virtual ions implanted in each substrate volume determined by the splitting depths. A first ion with selected velocity is input onto an impact position of the substrate that defines a first domain for the first ion during a first timestep, where the first domain includes only those atoms of the substrate that exert a force on the ion. A first position and velocity of the first ion is determined after the first timestep and a second domain of the first ion is formed at the first position. The first ion is split into first and second virtual ions if the first ion has passed through a splitting interval. The process then follows each virtual ion until all of the virtual ions have come to rest. A new ion is input to the surface and the process repeats until all of the ion dose has been input. The resulting ion rest positions form the simulated implant distribution.