Implications of lower zero-field activation energy of dielectric in Al2O3/HfO2 bi-layer dielectric RRAM forming process

Abstract

Bi-layer Al2O3/HfO2 dielectric RRAM shows reduction in forming voltage compared to single HfO2 layer RRAM device. It was found that Al2O3 dielectric has lower zero-bias activation energy which helps in faster filament growth than HfO2. In addition to low zero-bias activation energy, Al2O3 have lowerdielectric constant leading to higher electric field drop in Al2O3 layer. Incorporation of a thin Al2O3 dielectric in HfO2 based RRAMs lowers the forming voltage and increases the Ion/Ioff ratio without sacrificing the physical thickness. Therefore, Al2O3/HfO2 bi-layer dielectric RRAM can be a potential solution for future RRAM which can provide lesser forming voltage and higher Ion/Ioff ratio. © The Electrochemical Society.