Electrical stressing of bilayer insulator HfO2/Al2O3 metal-insulator-insulator-metal (MIIM) diodes

摘要

Bilayer metal/insulator/insulator/metal (MIIM) diodes of HfO2 and Al2O3 using asymmetric metal gates are investigated for their susceptibility to trap charge. Comparing the effects of constant current electrical stressing for varying thicknesses of insulators, the authors have formulated an adaptation of the Fowler-Nordheim derivative method such that an estimate of the charge centroid location can be obtained for bilayer insulators. In this work it has been found the addition of an HfO2 layer into an Al2O3 MIM device leads to increased charge trapping and greater shifts in the I-V characteristic.