CALIBRATION FOR THE MONTE CARLO SIMULATION OF ION IMPLANTATION IN RELAXED SIGE

摘要

SiGe-based CMOS devices have significant performance enhancements compared to pure silicon devices. We have extended our Monte Carlo ion implantation simulator for Si_(1-x)Ge_x targets in order to study the formation of shallow junctions. SiGe has a larger nuclear and electronic stopping power for ion implanted dopants compared to pure silicon due to the heavier and electron-rich germanium. It turned out that the Lindhard correction parameter of the electronic stopping model can be adjusted by a linear function of the germanium content to adopt the strength of the electronic stopping. The successful calibration for the simulation of arsenic and boron implantations in Si_(1-x)Ge_x is demonstrated by comparing the predicted doping profiles with SIMS measurements. Thereby the non-linear shift towards shallower profiles with increasing germanium fraction is analyzed. Finally, the simulation result of source/drain implants for a MOS-transistor structure on a SiGe substrate is presented.