Characterization of sputter-deposited SrZrO3 : Cr films on Si substrates for commercial memory device applications

Abstract

To study the influence of crystallinity of Cr-doped SrZrO3 (SZO:Cr) film on its resistive switching characteristics, SZO:Cr-based metal-oxide-metal (MOM) structures were deposited on SrTiO3 (100) single crystal for epitaxial growth and on Si substrate for polycrystalline growth by pulsed laser deposition. From current-voltage (I-V) measurements, epitaxial SZO:Cr-based MOM structures grown on SrTiO3 (100) substrates showed a high switching voltage over +/- 9 V,while polycrystalline SZO:Cr-based MOM structures grown on Si substrates showed much lower switching voltage below +/- 2.5 V. We assume that the lower switching voltage in polycrystalline SZO:Cr-based MOM structure is attributed to the easy formation of a conducting path (= current flow channel) related to various defects. In order to examine feasibility for commercial memory device applications, the polycrystalline SZO:Cr-based MOM structures were fabricated on Si substrates by off-axis RF sputtering, which is applicable to large scale deposition, and their memory properties were investigated. From these results, we suggest that sputter-deposited polycrystalline SZO:Cr film is a good candidate material for resistive random access memory (ReRAM) applications.