Implications of lower zero-field activation energy of dielectric in Al_2O_3/HfO_2 bi-layer dielectric RRAM forming process

摘要

Bi-layer Al_2O_3/HfO_2 dielectric RRAM shows reduction in forming voltage compared to single HfO_2 layer RRAM device. It was found that Al_2O_3 dielectric has lower zero-bias activation energy which helps in faster filament growth than HfO_2. In addition to low zero-bias activation energy, Al_2O_3 have lower dielectric constant leading to higher electric field drop in Al_2O_3 layer. Incorporation of a thin Al_2O_3 dielectric in HfO_2 based RRAMs lowers the forming voltage and increases the I_(on)/I_(off) ratio without sacrificing the physical thickness. Therefore, Al_2O_3/HfO_2 bi-layer dielectric RRAM can be a potential solution for future RRAM which can provide lesser forming voltage and higher I_(on)/I_(off) ratio.