We developed ultra-thin bilayers of ferroelectric/ /dielectric (FE/DE) and anti-ferroelectric/DE (AFE/DE) using Hf1−xZrxO2 , for use as DRAM cell capacitors. We optimized the thickness and composition of FE/DE and AFE/DE bilayers, in order to improve stored charges with the suppression of remnant charges. In addition, we fabricated 1X nm DRAM cells using the optimum condition of FE/DE and AFE/DE capacitors, and demonstrated their operation in DRAM cells.