Patent ID: 7197437

Claim:
A Monte Carlo ion implantation simulation method comprising: entering a structure of a target having a monocrystal area, ion implanting conditions, and a number of trial particles; implanting said trial particles, as ions to be implanted, into said target; and performing a Monte Carlo simulation with respect to said implanted trial particles by performing the steps of: finding, for each implanted trial particle that is in said monocrystal area, a unit cell in which said each implanted trial particle is present and finding a basic cell in which said each implanted trial particle is present among basic cells that form said unit cell; finding a directional range in which said each implanted trial particle travels; obtaining collision candidate atoms with their locations from a database according to said found basic cell and said directional range; setting a thermal vibration displacement for each of said collision candidate atoms that have not set thermal vibration displacement; calculating a collision parameter and free-flight distance for each of said collision candidate atoms; selecting, as a collision atom, one of said collision candidate atoms that has a collision parameter smaller than a predetermined maximum collision parameter and a smallest positive free-flight distance; and calculating a collision between said each implanted trial particle and said collision atom to find a after-collision location and momentum of said each implanted trial particle, wherein said collision candidate atoms include: atoms each satisfying “p<pmax−Vm” and “η>Vm” and having a smallest free-flight distance (η=ηmin); and atoms each satisfying “p<pmax+Vm” and “−Vm<η<ηmin+Vm” where p is a collision parameter with respect to said atom's vibration center, η a free-flight distance, pmax a maximum collision parameter, and Vm a predetermined large thermal vibration displacement; and implanting ions into a semiconductor device based on results of the Monte Carlo simulation.