ULTIMATE LIMIT FOR DEFECT GENERATION IN ULTRA-THIN SILICON DIOXIDE

Experimental and theoretical investigations are reported for defect ge neration by electrical stress in silicon dioxide and for the critical number of defects necessary to trigger destructive breakdown. Experime ntal evidence is presented showing that the critical number of defects reaches a limit when the oxide thickness is reduced below 2.7 nm. Per colation calculations are shown ta be consistent with this oxide thick ness limit representing the ''effective size'' of one defect spanning the oxide, connecting anode and cathode together. Also, these calculat ions show that not all of the defects are capable of triggering a dest ructive breakdown event. (C) 1997 American Institute of Physics.