Device Simulation for Effects of Mechanical Stress on Electrical Performances of nMOSFETs: The Impacts of Stress-Induced Change of Intrinsic Carrier Density

This paper discusses a numerical model for analysing the effects of mechanical stress on semiconductor devices. In other words, drift-diffusion device simulation is conducted using a physical model incorporating the effects of mechanical stress. Then, each impact of the stress-induced physical phenomena is analysed. In our previous study, three physical phenomena that were attributed to mechanical stress have been modeled in our electron mobility model, i.e., the changes in relative population, the momentum relaxation time and the effective mass of electrons in conduction-band valleys. In addition, in this study, the stress-induced change of intrinsic carrier density is modeled. Stress-induce variations of drain current characteristics on n-type Metal Oxide Semiconductor Field Effect Transistors (nMOSFETs) are evaluated using a drift-diffusion device simulator including above mentioned physical models. It is demonstrated that the impact of stress-induced change of intrinsic carrier density is small for our evaluated nMOSFETs.