Impact of Atomic Layer Deposition Co-Reactant Pulse Time on 65nm CMOS Integrated Hafnium Dioxide-based Nanoscale RRAM Devices

In this work, we have improved switching reliability of Hafnium Oxide (HfO
₂
) based CMOS integrated RRAM devices by tuning Atomic Layer Deposition (ALD) Co-reactant pulse time for HfO
₂
switching layer deposition. Three different pulse times for H
₂
O vapor pulses were chosen for this split: standard pulse time, 1.5X pulse time and 5X pulse time. Based on full wafer device testing results, the 5X pulse time RRAM devices showed higher mean forming voltages attributed to lower leakage current density. Additionally, 1T1R cells fabricated with 5X cycle time showed more than 2X improvement in memory window and significant reduction in HRS switching variability. We also report >95% switching yield and a sigma of <; 0.5 for cell-to-cell switching variability based on over 450 tested 1T1R devices across full 300 mm wafers, demonstrating the robustness of our process.