4.1 MCIMPL-- Three-Dimensional Monte-Carlo Ion Implantation

Ion implantation is the most widely used mechanism to introduce dopant atoms into a semiconductor region. The semiconductor is thereby exposed to an ion beam that hits the semiconductor surface. Ions enter the material through the surface and travel through the material until they reach the final position. The parameters that control the implantation process are implantation dose, beam energy, dopant species, and the angles (tilt angle, twist angle) under which the beam hits the surface.

The ion implantation technique can be accurately simulated by computing the trajectories of individual ions through the semiconductor region. As a particle travels through the material it loses energy by interacting with the atoms of the target material. Such collisions and therefrom resulting momentum changes are computed for every ion. The resulting implantation profile is finally given as the statistical distribution of the final positions of the implanted particles. The accuracy of the simulated profile directly corresponds to the number of simulated ions. A drawback of the Monte-Carlo simulation technique is its comparably large amount of computing power, which can be in the order of one to several days on modern computing environment. A full description of the Monte-Carlo algorithm as it is implemented in MCIMPL can be found in [55].