A review of compact modeling for phase change memory

Abstract

Phase change memory (PCM) attracts wide attention for the memory-centric computing and neuromorphic computing. For circuit and system designs, PCM compact models are mandatory and their status are reviewed in this work. Macro models and physics-based models have been proposed in different stages of the PCM technology developments. Compact modeling of PCM is indeed more complex than the transistor modeling due to their multi-physics nature including electrical, thermal and phase transition dynamics as well as their interactions. Realizations of the PCM operations including threshold switching, set and reset programming in these models are diverse, which also differs from the perspective of circuit simulations. For the purpose of efficient and reliable designs of the PCM technology, open issues and challenges of the compact modeling are also discussed.

Local structure effects of carbon-doping on the phase change material Ge2Sb2Te5

“…Phase change memory has been identified as a promising alternative to existing non-volatile memory technologies. [1][2][3][4][5][6][7] Phase change memory cells are composed of a volume of phase change material that switches between crystalline (conductive) and amorphous (resistive) phases. These phases are used to store high and low digital states, respectively, and the phase changes are driven through resistive heating pulses.…”

“…These phases are used to store high and low digital states, respectively, and the phase changes are driven through resistive heating pulses. 1,5,[8][9][10] The implementation of phase change memory cells is more simple and scalable than existing flash memory cells (e.g., floating gate cells), allowing for higher device density, lower power consumption, and lower device cost. 2,[5][6][7]9,[11][12][13] The leading candidate material for optimization of phase change memory is Ge 2 Sb 2 Te 5 (GST), a chalcogenide with fast crystallization and amorphization rates, as well as high resistivity contrast between its crystalline and amorphous states.…”

“…1,5,[8][9][10] The implementation of phase change memory cells is more simple and scalable than existing flash memory cells (e.g., floating gate cells), allowing for higher device density, lower power consumption, and lower device cost. 2,[5][6][7]9,[11][12][13] The leading candidate material for optimization of phase change memory is Ge 2 Sb 2 Te 5 (GST), a chalcogenide with fast crystallization and amorphization rates, as well as high resistivity contrast between its crystalline and amorphous states. 1,[3][4][5][6][7][8][14][15][16] A shortcoming of GST for use in phase change memory is the poor phase stability of its amorphous state.…”

“…2,[5][6][7]9,[11][12][13] The leading candidate material for optimization of phase change memory is Ge 2 Sb 2 Te 5 (GST), a chalcogenide with fast crystallization and amorphization rates, as well as high resistivity contrast between its crystalline and amorphous states. 1,[3][4][5][6][7][8][14][15][16] A shortcoming of GST for use in phase change memory is the poor phase stability of its amorphous state. Specifically, the relatively low crystallization temperature of GST (E140 1C) can result in unwanted crystallization during processing, high-temperature use, or long-term use.…”

OML-PCM: optical multi-level phase change memory architecture for embedded computing systems

“…As a result, it does not meet the demands of analytics-driven workloads [2]. EPCMC cells have a similar micro architecture and access granularity to DRAM chips, which makes them suitable for main memory applications [3]. Studies conducted in the recent past have analyzed the behavior of EPCM cells and estimated the voltage margin at partial lines [4].…”