Fully Si compatible SiN resistive switching memory with large self-rectification ratio

In this letter, we report unique unipolar resistive switching memory behaviors in the Ni/Si₃N₄/p-Si structure by controlling the impurity concentration of Si bottom electrode. It is found that we can decrease the reset current drastically by reducing dopant concentration by reducing dopant concentration, which helps low-power operation in the high density resistive switching memory array. Also, the samples with high impurity concentration exhibited ohmic conduction in the low-resistance state (LRS) while those with low dopant concentration below 10¹⁸ cm^-3 showed a remarkable self-rectifying behavior. The nonlinear metal-insulator-semiconductor (MIS) diode characteristics in the samples with low doping concentration (∼10¹⁸ cm^-3) are explained by the formation of Schottky barrier at the metal and semiconductor interface. As a result, we demonstrate high rectification ratio (>10⁵) between forward and reverse currents along with the robust nonvolatile properties including endurance cycles and retention from the devices with large self-rectification ratio. The high self-rectifying characteristics of Si₃N₄-based RRAM cell would be one of the most virtuous merits in the high-density crossbar array.