Impacts of Depth and Lateral Profiles of Fluorine Atoms in Gate Oxide Films on Reliability

Fluorine (F) implantation into gate poly-Si was used to incorporate F atoms in gate oxide films. Different F profiles in depth direction of gate oxide films were prepared. Enhanced segregation of F atoms at SiO2/Si interfaces was important for improvement of time dependent dielectric breakdown (TDDB) lifetime and suppression of hot carrier degradation. TDDB and low frequency noise dependences on gate length suggested that F profiles in lateral direction of gate oxide films should be cared for reliability of short channel devices.