Enhancement of t/sup bd/ of MOS gate oxides with a single-step pre-stress prior to a CVS in the fowler-nordheim regime

摘要

This work demonstrates that a pre-stressing step can enhance oxide reliability. Single-step pre-stresses were performed with a wide range of parameters prior to a constant voltage stress. It was found that the tbd increase due to the pre-stress has two limits and is dependent on both: pre-stress bias level and pre-stress time. A power law relation has been established between tbd and the charge injected during the pre-stress. It was found that the charge threshold for the onset of the tbd increase is much higher than the initially trapped positive charge.