Monte Carlo simulation for ultra-small MOS devices

This paper discusses advanced needs of Monte Carlo simulation approaches for MOS silicon devices scaled below 0.1 μm channel length. For predictive simulation over a wide range of biases, it is necessary to provide the Monte Carlo procedure with tuning capabilities to adjust the mobility through calibration of the interface roughness scattering. This is accomplished by introducing a semi-empirical procedure with a physical elastic scattering rate and an inelastic rate with tunable strength. To resolve the role of hot carriers in relation to oxide interface damage, it is also important to realize fully bipolar MOS simulation, so that one can analyze the transport of impact-ionization generated carriers and secondary ionization. As the devices become quite small, three-dimensional simulation can be not only feasible, but also necessary to resolve the granularity of doping profiles and the complete carrier-carrier and carrier-ion interactions. Issues of device Monte Carlo implementation on parallel environments are discussed, and a practical approach for resolving the short-range forces of the charge-charge interaction in three dimensionals is described. Several examples and preliminary results are presented to illustrate the various issues.