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

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 I_on/I_off 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 I_on/I_off ratio.