Dual-Layer Dielectric Stack for Thermally Isolated Low-Energy Phase-Change Memory

High reset energy is an ongoing issue for phase-change memory (PCM) devices. Prior work demonstrates that smaller PCM switching volume and thermal isolation can reduce the reset energy. In this paper, we fabricate and measure a planar confined PCM device with a multilayer dual-layer stack (D'S) of SiO
₂
/Al
₂
O
₃
insulator. Devices with contact area of 500 × 20 nm and lengths of 2 μm show exceptionally low reset energies of 18.25 ± 15.8 pJ and low reset current densities of 0.94 ± 0.51 MA/cm
²
. Implementing the D'S enables a 60% reduction in reset energy compared with SiO
₂
-isolated devices.