Sc-Centered Octahedron Enables High-Speed Phase Change Memory with Improved Data Retention and Reduced Power Consumption

Abstract

Phase change memory (PCM) with advantages of high operation speed, multilevel storage capability, spiking-timedependent plasticity, etc., has wide application scenarios in both Von Neumann systems and neuromorphic systems. In the automotive application, intelligent system not only needs high efficiency to handle massive data processing but also good robustness to retain the existing data against high working temperature. In this work, Scdoped GeTe is developed for PCM, which has achieved 120 °C data retention for 10 years, 6 ns operation speed, and 7 nJ low power consumption. The high data retention is attributed to the high coordination number of Sc and its strong bonds with Te atoms in the amorphous phase, which enhances the robustness of the atomic matrices. Sc-centered octahedrons in amorphous state provide a nucleation center, leading to fast crystallization. In the crystalline phase, Sc atoms occupy Ge vacancies to form a homogenous GeTe-like rhombohedral phase. The strong covalentlike Sc−Te bonds weaken the neighboring Ge−Te bonds, lowering energy for melting. Together with the increased energy efficiency originated from confined grain size, the reduced power consumption has been achieved. The improvements in data retention, speed, and power efficiency have made Sc-doped GeTe a promising candidate for high-performance automobile electronics application.

Y-Doped Sb2Te3 Phase-Change Materials: Toward a Universal Memory

“…To avoid these problems, a systematic screening of all transition-metal elements as proper dopants for Sb 2 Te 3 by high-throughput ab initio calculations was performed in our previous work, where Y, Sc, and Hg were screened out . The Sc-doped Sb 2 Te 3 phase-change alloy has recently been found to enable ultrafast crystal nucleation because of the formation of Sc-stabilized octahedral motifs in the amorphous phase. , Considering that Sc is of high price and easily oxidized and Hg has high toxicity, this work only investigated the effect of Y on the phase-change property of Sb 2 Te 3 . Our experimental scheme was first to synthesize Y x Sb 2– x Te 3 (0 ≤ x ≤ 0.333) nanopowders by a hydrothermal method and then to use the nanopowders to fabricate a single alloy target by a hot-press sintering process.…”

Phase‐change memory based on matched Ge‐Te, Sb‐Te, and In‐Te octahedrons: Improved electrical performances and robust thermal stability

“…On the basis of the Arrhenius law, the data retention temperature for 10 years ( T 10 ) is calculated to be 180°C two times higher than GST (85°C) 16 . Then, we compare the T 10 and T c of different dopants (like Sc, 11,17 Ti, 18,19 C, 20,21 N, 22 Si, 23 Ta, 12,24 and Al 25 ; modified phase‐change alloys are shown in Figure 2F). Notably, IGST material shows the superior thermal stability, meeting the high temperature required for the application in automobile systems (over 120°C).…”

Phase Change Materials for Nonvolatile, Solid‐State Reflective Displays: From New Structural Design Rules to Enhanced Color‐Changing Performance

“…In addition to color‐changing performance, cycling endurance is another important parameter for display applications. According to relevant references, the cycling endurance of GeTe is 4 × 10 4 −10 5 cycles, [ 50,51 ] which is lower than that of Ge 2 Sb 2 Te 5 (2 × 10 6 cycles). [ 52–54 ] Thus, Ge 2 Sb 2 Te 5 ‐based displays have a better cycleability performance, while GeTe‐based display should have a better color‐changing performance.…”