title: Ultrafast switching in nanoscale phase-change random access memory with superlattice-like structures.
abstract: Phase-change random access memory cells with superlattice-like (SLL) GeTe/Sb(2)Te(3) were demonstrated to have excellent scaling performance in terms of switching speed and operating voltage. In this study, the correlations between the cell size, switching speed and operating voltage of the SLL cells were identified and investigated. We found that small SLL cells can achieve faster switching speed and lower operating voltage compared to the large SLL cells. Fast amorphization and crystallization of 300 ps and 1 ns were achieved in the 40 nm SLL cells, respectively, both significantly faster than those observed in the Ge(2)Sb(2)Te(5) (GST) cells of the same cell size. 40 nm SLL cells were found to switch with low amorphization voltage of 0.9 V when pulse-widths of 5 ns were employed, which is much lower than the 1.6 V required by the GST cells of the same cell size. These effects can be attributed to the fast heterogeneous crystallization, low thermal conductivity and high resistivity of the SLL structures. Nanoscale PCRAM with SLL structure promises applications in high speed and low power memory devices.
authors.affiliation: NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, Singapore.
authors.forename: Desmond
authors.initials: D
authors.lastname: Loke
authors.forename: Luping
authors.initials: L
authors.lastname: Shi
authors.forename: Weijie
authors.initials: W
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Zhao
authors.forename: Hongxin
authors.initials: H
authors.lastname: Yang
authors.forename: Lung-Tat
authors.initials: LT
authors.lastname: Ng
authors.forename: Kian-Guan
authors.initials: KG
authors.lastname: Lim
authors.forename: Tow-Chong
authors.initials: TC
authors.lastname: Chong
authors.forename: Yee-Chia
authors.initials: YC
authors.lastname: Yeo