Non-volatile memory-based analog computation-in-memory can improve energy efficiency and latency of artificial intelligence edge devices by minimizing the movement of data between processors and memories. Here, we developed reliable HfO 2 -based resistive synaptic cell (RSC) arrays with 16-level analog properties. We revealed that oxygen diffusion barriers not only suppress the negative-set phenomenon and but also improve retention properties. In addition, we fully integrated 256Kcell 1T1R cross-bar RSC arrays using a conventional CMOS process, and demonstrated their improved multiply–accumulate operations with ~94% accuracy.