Oxide breakdown dependence on thickness and hole current - enhanced reliability of ultra thin oxides

The link between hole generation/trapping and oxide breakdown is demonstrated by correlating oxide breakdown with the hole current generated in the oxide. Both exhibit the same oxide thickness and field dependences. Charge-to-breakdown (QBD), time-to-breakdown (tBD), and breakdown-field (EBD) increase dramatically as oxide thickness is reduced below 80 Å due to reduced rate of hole generation, which is modeled by an average electron energy analysis. Time-dependent-dielectric-breakdown (TDDB) tests show that, for as-grown oxide capacitors, defect densities may decrease with decreasing oxide thickness down to 60 Å.