Patent ID: 6366873
Filing Date: 2002-04-02
Classification: G06F

Abstract:
A computer-implemented molecular dynamics-based process for simulating a distribution of ions implanted in a semiconductor substrate comprising the steps of:(a) initializing the properties of the semiconductor substrate and ion dose to be simulated, 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; (b) inputting a first ion with selected velocity onto an impact position of the substrate and initializing a first domain for the first ion during a first timestep, where the first domain includes all atoms of the substrate that exert a force on the ion and neighbor atoms; (c) determining a first position of the first ion after the first timestep; (d) forming a second domain of the first ion at the first position; (e) determining if the first ion has passed through a splitting depth; (1) if not, determining the velocity into the substrate of the first ion and initiating a second timestep; (2) if so, splitting the first ion into first and second virtual ions and determining a new velocity into the substrate of the first virtual ion after the first timestep and initiating a second timestep with the first virtual ion; (f) setting the first virtual ion, if created, as the first ion, the second timestep as the first timestep, and the second domain as the first domain; (g) repeating steps (c)-(e) and recording second virtual ions created at each splitting interval until the first ion comes to rest and a second virtual ion is recorded as the deepest split ion; (h) repeating steps (c)-(g) where the deepest split ion becomes the first ion until all of the ions resulting from splitting of the first ion come to rest; and (i) repeating steps (b)-(h) until all of the ions in the ion dose to be simulated have come to rest.