A new aspect of mechanical stress effects in scaled MOS devices

Deviation in device characteristics due to mechanical stress is investigated experimentally and analytically from the viewpoints of scaling and hot-carrier effects. A stress analysis program, SIMUS (stress analysis program for multilayer structure) 2D/F, which can analyze the stress state of thin multilayer structures such as LSI devices throughout their manufacturing process, was used. In scaled MOS devices, the effect of uniaxial stress is reduced. However, the effect of vertical stress, such as mold stress, becomes a serious problem when the vertical stress causes compressive surface stress. Compressive stress has a serious effect on electron trapping, in SiO_2. These results provide important guidelines for the manufacture and package design of deep submicrometer devices