Dramatic improvement of hot-electron-induced interface degradation in MOS structures containing F or Cl in SiO/sub 2/

Abstract
The effects of F and Cl incorporated in SiO/sub 2/ on the susceptibility of the metal/SiO/sub 2/ (MOS) interface to hot-electron damage have been studied. It has been found that, by introducing a very small amount of F or Cl in the thermal SiO/sub 2/, the generation of interface traps by Fowler-Nordheim tunneled hot electrons can be greatly suppressed. In addition, the gate-size dependence of hot-electron-induced interface traps, which is normally observed in samples made of dry oxides, does not appear in such chlorinated or fluorinated samples. When excess amounts of F or Cl are introduced into SiO/sub 2/, however, the benefits mentioned will diminish. The possible roles that F and Cl play that lead to the experimental observations are discussed.