Numerical study on impact of mechanical stress in the regions of high current density in N-Type MOS devices

This article shows numerical studies based on driftdiffusion device simulation for the effects of mechanical stress on n-type MOS devices. The device simulation incorporates an electron mobility model for illustrating the effects of stress. In this study, three numerical studies are conducted for the effects of mechanical stress on the electrical performance of an n-type MOS device: the effects of stress distribution in the device are simulated, dominant physical phenomena on electron mobility enhancement induced by stress are analyzed, and the impact of stress in the regions of high current density is examined. It is demonstrated that, quantitatively speaking, dominant physical phenomena is the change in the relative occupancy. It is shown that most of the stress effects result from stresses in the regions of high current density in the n-type MOS device.