Spatially confined electric field effect for improved resistive switching behavior of a Ni/Ta-embedded TaOx/NiSi device

Abstract

In this study, Ni/TaO_x/NiSi and Ni/TaO_x/Ta/TaO_x/NiSi devices were fabricated, and the resistive switching (RS) behaviors were investigated. A 2 nm-thick Ta metal layer was deposited between two TaO_x films to form a Ni/TaO_x/Ta/TaO_x/NiSi stack, which was analyzed using TEM. Based on a linear scale I–V curve and an R–V graph, both devices showed conventional bipolar conductive bridge random access memory (CBRAM) characteristics with formation/rupture of Ni conductive filaments (CFs). The Ta-embedded device showed lower forming/SET voltages and initial resistance due to the reduced effective thickness of TaO_x films due to the inserted Ta metal layer. In addition, the Ta-embedded device exhibited improved endurance and resistance distribution due to suppression of the random formation of Ni CFs. In this study, Ni/TaO_x/NiSi and Ni/TaO_x/Ta/TaO_x/NiSi devices were fabricated, and the resistive switching (RS) behaviors were investigated. A 2 nm-thick Ta metal layer was deposited between two TaO_x films to form a Ni/TaO_x/Ta/TaO_x/NiSi stack, which was analyzed using TEM. Based on a linear scale I–V curve and an R–V graph, both devices showed conventional bipolar conductive bridge random access memory (CBRAM) characteristics with formation/rupture of Ni conductive filaments (CFs). The Ta-embedded device showed lower forming/SET voltages and initial resistance due to the reduced effective thickness of TaO_x films due to the inserted Ta metal layer. In addition, the Ta-embedded device exhibited improved endurance and resistance distribution due to suppression of the random formation of Ni CFs.