Fiber Form GeS₂ OTS Device for Wearable Electronics

Recently, wearable device technology is growing at a rapid speed with interest in the market. Many wearable device products are introduced every year, and related research is being actively conducted accordingly. In order to maintain the flexible characteristics of wearable devices, researches related to bending and stretching of memory devices are also in progress. Resistive Random Access Memory (ReRAM), a next-generation memory device that works with a simple Metal-Insulator-Metal (MIM) structure, can overcome the flexibility limitations of conventional memory types by advantage of its structure. As a result, highly flexible wearable memories can be fabricated with ReRAM and applied to devices. However, disadvantages such as sneak current appearing in the cross-bar structure remain as problems.<br/><br/>Herein, we try to solve the sneak current problem of ReRAM by adding Ovonic Threshold Switching (OTS) material to the cross-bar structure of the conductive fibers, which are used as the metal layer. We partially deposited GeS2, which is a chalcogenide material, as OTS selector by RF sputtering on the Uniform Au nanoparticles coated fiber developed by our research team. We control the thickness of GeS₂ by sputter deposition time, and results show same V_th when GeS₂ have the same thickness. Through future research, it is possible to realize a very flexible memory device by depositing ReRAM material on the fiber and coating OTS material. Then we can put more useful memory devices in wearable electronics.