Fabrication and Characterization of Alumina Based Resistive RAM for Space Applications

In this paper, we have studied resistive random-access memory (ReRAM) which inherits excellent properties as a non-volatile memory in terms of higher speed, lower cost, higher storage density and scalability for applications in various fields. The memristor is a basic circuit element that results in the new type of non-volatile memory like ReRAM. The critical feature of memristor is the ability to retain its state without power, thus making it as a substitute for non-volatile memories in VLSI systems. We have explored the material properties, and studied electrical characteristics including resistance switching mechanism for the fabricated alumina based nonvolatile memory ReRAM. We have fabricated the MIM (Metal-Insulator-Metal) structure of ReRAM in the form of Au/Al2O3/Pt-Si. The insulator layer (Al2O3) was deposited on the platinized Si-Wafer by Atomic Layer Deposition technique. The top electrode is Au dots deposited using thermal Evaporator. Various characterization techniques such as XRD, AFM and SEM of the deposited ultra thin film were carried out to study the morphology of the dielectric layer. Pre-radiation I-V characteristics of the fabricated ReRAM was determined and the results have been studied. Our I-V characteristics show a typical bipolar switching for Au/Al2O3/Pt-Si ReRAM configuration. Post radiation studies would be carried out to determine the radiation hardness of ReRAM as a non-volatile memory for space applications.

I. Introduction

A resistive random-access memory made up memory cell comprising of two metals and insulator as metal-insulator-metal (MIM) structure. An external voltage source across the ReRAM cell triggers a change in resistance from a high resistance state (HRS), (OFF state) also mentioned as logic with value ‘0’ to a low resistance state (LRS), (ON state) mentioned as logic with value’ 1‘. The reverse of above-mentioned resistive change from low to high completes one full cycle. The resistive switching (RS) or resistive change mechanism is reflected as the underline cause behind the change in resistive state of the single ReRAM cell.