Title :
A Unified Hopping Model for Subthreshold Current of Phase-Change Memories in Amorphous State
Author :
Calderoni, Alessandro ; Ferro, Massimo ; Ielmini, Daniele ; Fantini, Paolo
Author_Institution :
Adv. R&D, Numonyx, Agrate Brianza, Italy
Abstract :
The conduction process of phase-change-memory (PCM) devices in the amorphous high-resistance state is described by a trap-limited transport model. Based on numerical simulations of the barrier lowering in a potential landscape due to localized charged states, we propose a physically based analytical hopping model accounting for the different voltage dependence of current characteristics in the low- and high-field regimes. The analytical model is able to accurately describe, with the same set of parameters, the experimental behavior of both the temperature-dependent I- V curves and the voltage-dependent activation energy for conduction. Comparison with experimental data is provided, demonstrating the physical consistency of the proposed model.
Keywords :
hopping conduction; phase change memories; PCM devices; amorphous high-resistance state; analytical hopping model; current characteristics; numerical simulations; phase change memories; subthreshold current; temperature-dependent I-V curves; trap-limited transport model; unified hopping model; voltage-dependent activation energy; Amorphous materials; Analytical models; Conducting materials; Crystalline materials; Crystallization; Phase change materials; Phase change memory; Predictive models; Subthreshold current; Voltage; Amorphous chalcogenide; Poole–Frenkel (PF) conduction; phase-change memory (PCM); transport modeling;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2010.2052016