Novel nanocomposite-superlattices for low energy and high stability nanoscale phase-change memory

Xiangjin Wu; Asir Intisar Khan; Hengyuan Lee; Chen-Feng Hsu; Huairuo Zhang; Heshan Yu; Neel Roy; Albert V Davydov; Ichiro Takeuchi; Xinyu Bao; H-S Philip Wong; Eric Pop

doi:10.1038/s41467-023-42792-4

Novel nanocomposite-superlattices for low energy and high stability nanoscale phase-change memory

Nat Commun. 2024 Jan 22;15(1):13. doi: 10.1038/s41467-023-42792-4.

Authors

Xiangjin Wu^#¹, Asir Intisar Khan^#¹, Hengyuan Lee², Chen-Feng Hsu², Huairuo Zhang^{3

4}, Heshan Yu^{5

6}, Neel Roy¹, Albert V Davydov³, Ichiro Takeuchi⁵, Xinyu Bao⁷, H-S Philip Wong¹, Eric Pop^{8

9

10}

Affiliations

¹ Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
² Corporate Research, Taiwan Semiconductor Manufacturing Company (TSMC), Hsinchu, Taiwan.
³ Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
⁴ Theiss Research, Inc., La Jolla, CA, USA.
⁵ Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA.
⁶ School of Microelectronics, Tianjin University, Tianjin, China.
⁷ Corporate Research, Taiwan Semiconductor Manufacturing Company (TSMC), San Jose, CA, USA.
⁸ Department of Electrical Engineering, Stanford University, Stanford, CA, USA. epop@stanford.edu.
⁹ Department of Materials Science & Engineering, Stanford University, Stanford, CA, USA. epop@stanford.edu.
¹⁰ Precourt Institute for Energy, Stanford University, Stanford, CA, USA. epop@stanford.edu.

^# Contributed equally.

Abstract

Data-centric applications are pushing the limits of energy-efficiency in today's computing systems, including those based on phase-change memory (PCM). This technology must achieve low-power and stable operation at nanoscale dimensions to succeed in high-density memory arrays. Here we use a novel combination of phase-change material superlattices and nanocomposites (based on Ge₄Sb₆Te₇), to achieve record-low power density ≈ 5 MW/cm² and ≈ 0.7 V switching voltage (compatible with modern logic processors) in PCM devices with the smallest dimensions to date (≈ 40 nm) for a superlattice technology on a CMOS-compatible substrate. These devices also simultaneously exhibit low resistance drift with 8 resistance states, good endurance (≈ 2 × 10⁸ cycles), and fast switching (≈ 40 ns). The efficient switching is enabled by strong heat confinement within the superlattice materials and the nanoscale device dimensions. The microstructural properties of the Ge₄Sb₆Te₇ nanocomposite and its high crystallization temperature ensure the fast-switching speed and stability in our superlattice PCM devices. These results re-establish PCM technology as one of the frontrunners for energy-efficient data storage and computing.