Hot carrier reliability in deep submicrometer MOSFETs

The authors examine the hot carrier reliability in MOSFETs with channel lengths ranging from 0.95 to 0.15 mu m. It was found that the lifetime plot, tau -I/sub d/-I/sub sub//I/sub d/, for the above channel lengths showed a unique straight line and was independent of the channel length when tau was defined as the stress time to generate a fixed number of interface states. This result shows that the hot-electron degradation model used for longer channel devices is also applicable in the deep submicrometer regime. On the other hand, when tau was defined as the time to cause a fixed drain current reduction, the lifetime plot was dependent on the channel length. This difference in the two lifetime plots was caused by the nonscalability of the damaged region, so that the hot carrier energy for deep submicrometer MOSFETs must be reduced.<>