Atomistic Modeling of CBRAM Switching Behavior
Quantum Transport in Complete Device Geometries
• Develop predictive
atomistic models for
Completed Partial
filament filament
CBRAM.
• Provide input & insight to
improve device
performance.
Results:
• End to end device simulations.
Geometry
(3×3nm2
nanowire)
5
Energy [eV]
Objectives:
4
1
V
3
High
Resistance
2
Observed filaments in thin films.
Lu et al. Nature Comm. 3, 732 (2012)
-6
-5
-4
-3
-2
-1
Ef2
Ef1
0
10 10 10 10 10 10 10
Transmission
Predicted current ratio for high/low
resistance state ILR/IHR=103
-5
10
-6
10
Current [A/nm 2]
Approaches & Accomplishments:
• Tight-binding model developed for Cu/SiO2.
• Geometry relaxation & electrochemical
processes simulated by molecular dynamics
(MD). Structures are imported into NEMO5.
• Charge densities are calculated by MD and
imported into NEMO5. Electrostatic potential
are calculated from charge densities.
• Coherent current through relaxed structures
calculated by tight-binding.
Low Resistance
-7
10
-8
10
-9
10
-10
10
-11
10
-12
10
-13
10
0
500
1000
Time [ps]
1500
Non-monotonic character of current evolution is
consistent with the ab-initio results