Monte Carlo Simulation of Ion Implantation for Doping of Strained Silicon MOSFETs

Abstract—Strain is recognized as one of the key technology features to increase the drive current in scaled MOS devices. We present a Monte Carlo simulation study for introducing dopants into a strained Si/Si1-xGexsystem at very low energies. The lattice constant in the epitaxial growth direction of the biaxial tensile strained silicon layer is calculated according to the elastic theory. The accuracy of the simulation results is evaluated by comparing the predicted boron and arsenic doping profiles with SIMS measurements. It was found that the predicted arsenic distribution in strained silicon shows a slightly deeper penetration compared to unstrained silicon due to the stress-induced volume dilation. Finally the simulation result of source/drain and extension implants into a three-dimensional strained silicon MOS structure with an STI isolation scheme is presented.