Operating Current Reduction in Nickel Oxide Correlated Electron Random Access Memories (CeRAMs) Through Controlled Fabrication Processes

Abstract

Low temperature process for metal organic decomposition (MOD) derived stable and charge compensated thin NiO films is presented. The coordination number ‘fine tuning’ in nickel oxide Correlated Electron Random Access Memories (CeRAMs) is obtained via carbonyl ligand doping. Further regulation of the number of oxygen vacancies and the surface excess of metal ions is realized by selecting the most stable metal-oxide interfaces. Inserting the ultrathin homo- or heterogeneous oxide layers or oxygen diffusion barriers into the top metal-oxide interface is just one example. We have demonstrated the improved performance of the CeRAM cell obtained by a combination of material doping, layer grading, oxygen diffusion barrier and the small cell sizes. It is shown that optimization of various process conditions leads to the endurance parameters improvement and the write current reduction for relatively large device areas with external compliance circuitry. Further current reduction through the cell size scaling and the on-chip compliance circuitry will ensure CeRAM's programming speed sufficient for high-speed performance. These factors combined together unfold a novel opportunity for the fabrication of a memory cell with superior characteristics for universal high-density non-volatile memory.