Performance comparison of titanium-oxide resistive switching memories using GeO_x and AlO_x capping layers for flexible application

To meet the requirements of flexible memory applications, we have compared two capping layers of GeO_x and AlO_x on a TiO_y resistive random access memory (RRAM) at room temperature. A Ni/GeO _x/TiO_y/TaN RRAM shows a large resistance window of >10², 85 °C retention, a highresistance-state (HRS) activation energy (E_a) of 0.52 eV, and a good DC cycling of 10³ cycles, which are significantly better than those of a Ni/ AlO _x/TiO_y/TaN RRAM, which has a high-defect-density dielectric of AlO_x.