Ultralow‐Power Programmable 3D Vertical Phase‐Change Memory with Heater‐All‐Around Configuration

Abstract

Recent advancements in phase‐change memory (PCM) technology have predominantly stemmed from material‐level designs, which have led to fast and durable device performances. However, there remains a pressing need to address the enormous energy consumption through device‐level electrothermal solutions. Thus, the concept of a 3D heater‐all‐around (HAA) PCM fabricated along the vertical nanoscale hole of dielectric/metal/dielectric stacks is proposed. The embedded thin metallic heater completely encircles the phase‐change material, so it promotes highly localized Joule heating with minimal loss. Hence, a low RESET current density of 6–8 MA cm⁻² and operation energy of 150–200 pJ are achieved even for a sizable hole diameter of 300 nm. Beyond the conventional 2D scaling of the bottom electrode contact, it accordingly enhances ≈80% of operational energy efficiency compared to planar PCM with an identical contact area. In addition, reliable memory operations of ≈10⁵ cycles and the 3‐bits‐per‐cell multilevel storage despite ultrathin (<10 nm) sidewall deposition of Ge₂Sb₂Te₅ are optimized. The proposed 3D‐scaled HAA‐PCM architecture holds promise as a universally applicable backbone for emerging phase‐change chalcogenides toward high‐density, ultralow‐power computing units.