Mater. Res. Soc. Symp. Proc. Vol. 1729 © 2015 Materials Research Society DOI: 10.1557/opl.201 . Unipolar resistive switching behavior of high-k ternary rare-earth oxide LaHoO 3 thin films for non-volatile memory applications Yogesh Sharma, Pankaj Misra, Shojan P. Pavunny, and Ram S. Katiyar Department of Physics and Institute for Functional Nanomaterials, University of Puerto Rico, PR-00936-8377, USA ABSTRACT Rare-earth oxides have attracted considerable research interest in resistive random access memories (ReRAMs) due to their compatibility with complementary metal-oxide semiconductor (CMOS) process. To this end we report unipolar resistive switching in a novel ternary rare-earth oxide LaHoO 3 (LHO) to accelerate progress and to support advances in this emerging densely scalable research architecture. Amorphous thin films of LHO were fabricated on Pt/TiO 2 /SiO 2 /Si substrate by pulsed laser deposition, followed by sputter deposition of platinum top electrode through shadow mask in order to elucidate the resistive switching behavior of the resulting Pt/LHO/Pt metal-insulator-metal (MIM) device structure. Stable unipolar resistive switching characteristics with interesting switching parameters like, high resistance ratio of about 10 5 between high resistance state (HRS) and low resistance state (LRS), non-overlapping switching voltages with narrow dispersion, and excellent retention and endurance features were observed in Pt/LHO/Pt device structure. The observed resistive switching in LHO was explained by the formation/rupture of conductive filaments formed out of oxygen vacancies and metallic Ho atom. From the current-voltage characteristics of Pt/LHO/Pt structure, the conduction mechanism in LRS and HRS was found to be dominated by Ohm’s law and Poole-Frenkel emission, respectively. INTRODUCTION Simple design, excellent scalability, high switching speed, and compatibility with complementary metal–oxide–semiconductor process make resistive random access memory (ReRAM) a potential candidate for nonvolatile data storage [1-3]. Some rare-earth oxides showed electrical field induced change of resistivity where the presence of two different resistance states namely a high-resistance state (OFF-state) and a low-resistance state (ON-state) serve as the basis of memory storage [4]. Rare-earth oxide-based ReRAM with the features of stable non-volatile unipolar and/or bipolar resistive switching has been proposed for the embedded application including multi-level storage capability and excellent reliability [4]. Generally, the resistive switching (RS) mechanism in rare-earth oxides based ReRAM device can be explained by the well-accepted conductive filamentary model where several nanometer- sized filaments are formed by the agglomeration of existing or field induced chemical defects (i.e., metallic rare-earths and oxygen vacancies) during the electro-forming process [4-6]. Recently, we reported nonvolatile multilevel resistive memory behavior in thin films of one of the ternary rare-earth oxides SmGdO 3 (SGO) [7]. The stable 4-level resistance states of the Pt/SGO/Pt device with sufficient margin of resistance ratios (ON/OFF) were demonstrated and 5 92