Electro-Thermal Confinement Enables Improved Superlattice Phase Change Memory

Large switching current density and resistance drift remain challenges for phase change memory (PCM) in data storage and neuromorphic computing applications. Here, we address these by electro-thermal and structural confinement in a GeTe/Sb2Te3superlattice PCM (SL-PCM) with thermally-induced phase change, while observing scalability with bottom electrode diameter. We demonstrate ~8-10×reduction of reset current density(Jᵣₑₛₑₜ)and ~25-30×reduction of power(Pᵣₑₛₑₜ)in our mushroom cell SL-PCM compared to control Ge2Sb2Te5(GST) PCM with the same device structure. The SL-PCM devices also exhibit multi-level states with~ 10×lower resistance drift compared to control GST PCM. Material characterization and electro-thermal simulations confirm the role of heat confinement in SL-PCM, paving the way towards low-power, high-density memory and data storage.