AC-DC factor sensitivity for DRAM components lifetime under hot-carrier injection

Abstract

Estimating operating lifetime is critical for dynamic random access memory (DRAM) components with hot-carrier injection (HCI). Using DC device lifetime to substitute a component lifetime can be too pessimistic and can disqualify good DRAM products. This work proposes the DC to AC lifetime ratio factor and its sensitivity over three parameters: device degradation, effective drain voltage in word-line driving circuit, and access frequency. The timing margin in word-line driver signal is directly related to HCI degradation and correlated to DC to AC lifetime ratio. The results are discussed with measured I sub current in three different technologies and DRAM components, and correlated with both simulation and test data. © 2011 IEEE.