Reliability issue of 20 nm MLC NAND Flash

We report reliability issues of MLC NAND Flash memories due to the cell size scaling down to 20nm. For word line (WL) air-gap process to overcome the Floating gate (FG) - FG coupling [1], we have investigated the hydrogen effect of Inter-Layer-Dielectric (ILD) materials on reliability characteristics. We also demonstrate different charge loss phenomenon through Inter-Poly-Dielectric (IPD) on 20nm cells by the IPD scaling due to narrow FG to FG isolation space from measured lower activation energy(Ea) value (0.33 eV) than previously reported.