Arsenic-free ovonic threshold switch for next-generation selectors in 3-dimensional cross-point memories

Abstract

Ovonic threshold switch (OTS) has been considered for use as a selector in 3-dimensional (3D) cross-point memories. Arsenic-containing materials such as the Ge-As-Si-Te-N system have been proposed for the switching of OTS devices. However, as is toxic to both humans and the environment, such materials are generally avoided. Here, high-performance OTS devices are demonstrated using As-free material, i.e., a Ga-N-Sb-Te layer, which exhibits promising threshold switching characteristics. The Ga-N-Sb-Te thin film was deposited by co-sputtering process at 298 K. The OTS device based on the Ga-N-Sb-Te material exhibited a large ON current density (>10 MA/cm2) with long cycling endurance (>107), thus can be considered a promising candidate for use as a selector for 3D cross-point memories.