Lowest I<sub>OFF</sub> < 3×10<sup>−21</sup> A/μm in capacitorless DRAM achieved by Reactive Ion Etch of IGZO-TFT
Attilio Belmonte, Shreya Kundu, Subhali Subhechha, Adrian Chasin, Nouredine Rassoul, H.F.W. Dekkers, Harinarayanan Puliyalil, F. C. Seidel, Patrick Carolan, Romain Delhougne, Gouri Sankar Kar
Abstract
We demonstrate that the retention of IGZO-based 2T0C devices is boosted by patterning the active module by RIE. While IBE generates Al redeposition on the device sidewalls creating an extrinsic conductive path, RIE enables a clean process which suppresses metal redeposition. With RIE, we achieve the lowest $\mathrm{I}_{\mathrm{O}\mathrm{F}\mathrm{F}}$ ever reported for 2T0C cells (<3× 1$0^{-21}$A/$\mu$m), and we successfully perform multi-level and multiply-accumulate operations enabling machine-learning applications. We also demonstrate device functionality down to $\mathrm{L}_{\mathrm{G}}$=25nm.