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Filament-to-dielectric band alignments in $$\hbox {TiO}_{2}$$ TiO 2 and $$\hbox {HfO}_{2}$$ HfO 2 resistive RAMs
- Source :
- Journal of Computational Electronics. 16:1057-1065
- Publication Year :
- 2017
- Publisher :
- Springer Science and Business Media LLC, 2017.
-
Abstract
- The next-generation nonvolatile memory storage may well be based on resistive random access memories (RRAMs). $$\hbox {TiO}_{2}$$ and $$\hbox {HfO}_{2}$$ have been widely used as the resistive switching layer for RRAM devices. However, the electronic properties of the filament-to-dielectric interfaces are still not well understood yet, compared to those of the electrodes and the dielectric. In this work, we study the electronic structures of three typical filament and dielectric structures, $$\hbox {Ti}_{4}\hbox {O}_{7}/\hbox {TiO}_{2}$$ , $$\hbox {Hf}_{2}\hbox {O}_{3}/\hbox {HfO}_{2}$$ and $$\hbox {Hf}/\hbox {HfO}_{2}$$ , using ab initio calculations. We implement the GGA-1/2 method, which rectifies the band gaps of GGA through self-energy correction. Our calculation predicts an ohmic contact for the $$\hbox {Ti}_{4}\hbox {O}_{7}/\hbox {TiO}_{2}$$ interface, where the defective $$\hbox {Ti}_{4}\hbox {O}_{7}$$ phase was experimentally identified as the filament composition in $$\hbox {TiO}_{2}$$ . However, there is a finite Schottky barrier existing in either $$\hbox {Hf}_{2}\hbox {O}_{3}/\hbox {HfO}_{2}$$ interface (1.96 eV) or $$\hbox {Hf}/\hbox {HfO}_{2}$$ interface (0.61 eV), the two probable filament–dielectric configurations in hafnia-based RRAM. Our results suggest that the distinct filament-to-dielectric band alignments in $$\hbox {TiO}_{x}$$ and $$\hbox {HfO}_{x}$$ systems account for the much larger resistance window for the latter.
- Subjects :
- 010302 applied physics
Resistive touchscreen
Materials science
Band gap
Schottky barrier
02 engineering and technology
Dielectric
021001 nanoscience & nanotechnology
01 natural sciences
Atomic and Molecular Physics, and Optics
Electronic, Optical and Magnetic Materials
Protein filament
Crystallography
Ab initio quantum chemistry methods
Modeling and Simulation
Resistive switching
0103 physical sciences
Electrical and Electronic Engineering
0210 nano-technology
Ohmic contact
Subjects
Details
- ISSN :
- 15728137 and 15698025
- Volume :
- 16
- Database :
- OpenAIRE
- Journal :
- Journal of Computational Electronics
- Accession number :
- edsair.doi...........5cb9104c80f265a6fc45407aa4cc9b49