Evaluation of Stress-Induced Effects in Electronic Characteristics of nMOSFETs

Stress-induced shifts in the DC characteristics of nMOSFETs were investigated experimentally by the 4-point bending method. We measured the device shape dependence and load direction dependence of the DC characteristic shifts. We also carried out drift-diffusion device simulation in order to evaluate the experimental results. The simulation model includes the electron mobility model that takes the stress effects into consideration. The conduction band energy change induced by the shear deformation of silicon is considered in the mobility model. The experimental results were evaluated reasonably using the proposed mobility model