Evolution of oxygen vacancies under electrical characterization for HfO x -based ReRAMs

Recently, studies on ReRAMs and their reliability have received increased attention. The reliability issue is due to the nature of oxygen vacancies behaviour under biasing conditions which necessitate further studies to achieve an in-depth understanding. In this work, we fabricated several HfOx ReRAM devices with different structure, material, and thickness, followed by a study of their electrical characteristics under DC biasing. We show an improvement in the switching parameters through engineering of the device structure. Moreover, we demonstrate a certain required thickness for the oxide layer for the ease of oxygen vacancies relocations, thinner oxide layer led to the common ReRAMs performance failure in the low resistance state.