Substrate dependent analysis of MIM Capacitors for Resistive random-access memory Applications

Abstract

Simple construction, great CMOS compatibility, low operation current/voltage, high density, and super rapid switching rates (10ns), has made resistive random-access memory (RRAM) one of the most desirable new Non-volatile Memory [1-4]. Transition-Metal-Oxides have been demonstrated to be excellent RRAM materials [3]. Also due to the generation of oxygen vacancies, ion irradiation has been found to improve RRAM properties [4]. Because of its fab-friendly properties and dielectric constant (k=10), ZnO is one of the most promising materials among them.

The present study focusses on the fabrication of Metal/MOx/Metal for RRAM application. The conduction behaviours which is responsible for switching behaviours in the Low resistance state (LRS) and High resistance state (HRS) non-volatile switching has been analysed in detail. A ZnO thin film with a thickness of 120-140 nm was grown on Au deposited Si and ITO coated glass substrate as shown in Fig. 1. The stoichiometry of metal oxide film has been measured by Resonant Rutherford back Scattering (RRBS) of ZnO coated Au deposited Silicon available at IUAC, Delhi as shown in Fig 2.

X-ray diffraction (XRD) analysis was used to characterize the crystalline structures of Au-deposited ZnO on ITO samples. The X-ray diffraction data for a typical ITO/ZnO/Au heterostructure is shown in the Fig 3 below. It was observed that the desired (002)-oriented ZnO wurtzite phase exists. With the use of pressure contact, we have investigated I-V characteristics and determined that ZnO with ITO coated substrate provides the best switching behaviour. The identical model was designed using COMSOL Multiphysics [5-6] software was used for validation, and the metal rich characteristics enhancement is studied as shown in Fig 4