R&D: Sputter-Grown GeTe/Sb2Te3 Superlattice Interfacial PCM for Low Power and MLC Operation

Electronics Letters has published an article written by Soo-Min Jin, Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul, Republic of Korea, Shin-Young Kang, Department of Materials Science, Tohoku University, Sendai, Japan, Hea-Jee Kim, Ju-Young Lee, Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul, Republic of Korea, In-Ho Nam, Department of Electronics Engineering, Hanyang University, Seoul, Republic of Korea, Tae-Hun Shim, Advanced Semiconductor Materials and Devices Development Center, Hanyang University, Seoul, Republic of Korea, Yun-Heub Song, Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul, Republic of Korea, and Department of Electronics Engineering, Hanyang University, Seoul, Republic of Korea, and Jea-Gun Park, Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul, Republic of Korea, Department of Electronics Engineering, Hanyang University, Seoul, Republic of Korea, and Advanced Semiconductor Materials and Devices Development Center, Hanyang University, Seoul, Republic of Korea.

Abstract: “The multi-level feature of GeTe/Sb₂Te₃ interfacial phase change memory was achieved by applying a designed voltage-based pulse. It stably demonstrated five multi-level states without interference for 90 cycles by varying the pulse width. GeTe/Sb₂Te₃ interfacial phase change memory demonstrated retention time of > 1.0 × 10³ s, presenting the significantly low drift coefficient (ν) of < 0.009, indicating no resistivity drift due to the structure relaxation of glass. In addition, the reset energy consumption of GeTe/Sb₂Te₃ interfacial phase change memory was reduced by more than 85% compared to conventional Ge₂Sb₂Te₅ phase change memory at each bottom electrode contact size. Multi-level-cell operation mechanism and gradual increase in conductance value of GeTe/Sb₂Te₃ interfacial phase change memory was explained by a partial resistance transition model where phase transition occurred partially in all layers. The result of the GeTe/Sb₂Te₃ interfacial phase change memory performance is expected to bring great advantages to the next-generation storage class memory industry that requires low energy and high density.“