First Demonstration of Ge2Sb2Te5-Based Superlattice Phase Change Memory with Low Reset Current Density (~3 MA/cm2) and Low Resistance Drift (~0.002 at 105°C)

Superlattice (SL) heterostructures have shown promise to reduce the reset current density (J
reset
) and resistance drift coefficient (v) of phase change memory (PCM). However, SLs have not been studied with the well-known phase change material Ge
2
Sb
2
Te
5
(GST), and the effect of SL interfaces and intermixing layers also remains unknown. Here, using SLs based on GST/Sb
2
Te
3
for the first time, we simultaneously achieve J
reset
≈ 3-4 MA/cm
²
and 7 resistance states (v ≈ 0.002) in mushroom-cell PCM with bottom electrode diameter down to 110 nm. The low J
reset
and v are retained even after 10
⁶
cycles and at high temperature (105°C), respectively. We also uncover that both J
reset
and v in SL-PCM decrease with increasing number of SL interfaces – but SL intermixing increases both, also showing up as evidence in thermal conductivity and X-ray diffraction measurements. This study advances SL-PCM technology for high-density storage and neuromorphic applications.