Schottky-like behavior of progressive breakdown of polycrystalline- silicon/silicon oxynitride gate dielectric stack

Abstract

The postbreakdown (BD) I-V characteristics of a relatively stable percolation path within ultrathin silicon oxynitride have been found to exhibit Schottky-like behavior. The ideality factors in the range of 1.3–1.7 indicate that a Schottky-like barrier could exist in controlling the conduction mechanism in the later stage of progressive BD (PBD). The extracted effective barrier heights associated with the percolation path provides possible insights into the nature of the percolation path. We found that there are two possible mechanisms governing the post-BD I-V characteristics in the later stage of PBD: (1) a material property change in the vicinity of the percolation path and (2) the percolation path dilation.