Ga₂Te₃Sb₅—A Candidate for Fast and Ultralong Retention Phase‐Change Memory

Abstract

Incongruent melting phenomenon shows the feasibility of multilevel control using the phase‐change material Ga2Te3Sb5 (Ga‐TS). Electrical results showed that Ga‐TS cells require 25% less RESET current than do GST cells. Meanwhile it possesses a high programming speed, ultralong data retention extrapolated to one million years at 120 °C, and superior thermal properties for phase‐change random‐access‐memory applications.

Superlattice-like electrode for low-power phase-change random access memory

“…Growth-dominated crystallization mechanism of PCL could be responsible for the ultra-fast switching speed. [15][16][17] It is also shown that the SLEbased PCRAM has smaller value of set voltage than the CEbased one at the pulse width of 5 ns, further suggesting lower power of the SLE-based PCRAM.…”

“…The top electrode fabricated alternately by TiN and W layers was embedded in PCRAM to achieve low power. Since Ga-Sb-Te ternary materials show fast speed and brilliant data retention in comparison with those of widely used Ge 2 Sb 2 Te 5 (GST), 15,16 it is used as a PCL for PCRAM in this study.…”

The crystallization behavior of stoichiometric and off-stoichiometric Ga–Sb–Te materials for phase-change memory

“…The Ga 4 Sb 6 Te 3 ͑E͒ also performs at fast speed comparable to Ga 2 Sb 5 Te 3 ͑C͒, which has been demonstrated to have fast set performance ͑ϳ20 ns͒ and very long data retention for phase-change memory. 9 It is also indicated that by raising the Sb/Te atomic ratio ͑from 1.22 to 1.95͒ with GaSb incorporation the crystallization speed can be further increased while the low Sb/Te ratio ͑0.79͒ material is the slowest. Similar results were demonstrated for In doped Sb-Te phase-change material.…”

Sb52Se36Te12 material with high-temperature data retention coupled with rapid crystallization speed for phase change application

“…Moreover, the thermal cross-talk between neighboring cells which will be more severe in high-density memory arrays requires higher stability of the amorphous phase to boost data retention performances of PCM [1]. What is more, there are also other issues such as the high reset current and slow speed of amorphous-to-crystalline phase transition that need to be addressed [10][11][12]. Thermal stability and transformation speed are two main features that can be further improved for practical applications of PCM [13][14][15].…”

“…Chalcogenide materials, such as Ge 2 Sb 2 Te 5 (GST), have been widely studied and utilized for PCM applications due to its excellent overall performances [5,6]. However, GST has a low crystallization temperature (about 150 C [6,7]), which leads to poor data retention just sufficient for some consumer applications (85 C for 10 years [8,9]), far away from the requirements of automotive system (120 C for10 years [10]). Moreover, the thermal cross-talk between neighboring cells which will be more severe in high-density memory arrays requires higher stability of the amorphous phase to boost data retention performances of PCM [1].…”