Effect of high temperature annealing on tunnel oxide properties in TANOS devices
We investigate the effect of high temperature Post-Deposition Annealing of Al2O3 on the tunnel oxide of TANOS-like non-volatile memories. We found that, when temperature steps above 850C are applied after the stack deposition, a transition layer is forming by the intermixing of the Si3N4 with the upper part of the underneath SiO2. We found that this transition layer has worse dielectric properties as compared to SiO2, altering in a not-negligible way the performance of TANOS memories, and in particular severely penalizing retention.
tanos intermixing high temperature pda