(Invited) Metal-Insulator-Metal Devices with High-K Dielectric for Nonvolatile or Dynamic Random Access Memories

Abstract

This paper presents an overview of our work on metal-insulator-metal (MIM) structures used for resistive non-volatile resistive (RRAM) or dynamic (DRAM) random access memories. Atomic layer deposition technique is used to grow the insulator layer. ALD allows monolayer thickness precision of deposited layers and flexible in-situ doping capabilities. Thanks to a suitable choice of the bottom, top electrodes and the dielectric, DRAM or RRAM functionality is enabled. It will be shown how we managed to tackle the main challenge in DRAM field where high dielectric constant along with minimum leakage current should be performed. For RRAM, the main challenge is to obtain reversible MIM resistance switching at low power and high Roff/Ron ratio. The switching mechanism in RRAM, usually attributed to oxygen vacancies percolation leading to a conduction path, has been studied with a focus on the role of the electrodes affinity to oxygen and their electron injection efficiency.