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Characterization and Modeling of Co/BaTiO3/SrRuO3 Ferroelectric Tunnel Junction Memory by Capacitance–Voltage (${C}$ –${V}$ ), Current–Voltage (${I}$ –${V}$ ), and High- Frequency Measurements
- Source :
- IEEE Transactions on Electron Devices. 66:2186-2191
- Publication Year :
- 2019
- Publisher :
- Institute of Electrical and Electronics Engineers (IEEE), 2019.
-
Abstract
- Ferroelectric tunnel junction (FTJ) is a promising low power nonvolatile memory for beyond-CMOS applications. In this paper, Co/BaTiO3/SrRuO3 FTJs are fabricated, simulated, and their electrical characteristics are measured by capacitance–voltage ( ${C}$ – ${V}$ ), current–voltage ( ${I}$ – ${V}$ ), and high-frequency S-parameter measurements. Ferroelectricity of the ultrathin BaTiO3 (~3.2 nm) film is first verified by a butterfly shaped hysteresis ${C}$ – ${V}$ profile, from which saturation polarizations are calculated in the ON state and OFF state as ${P}_{ \mathrm{ON}}=+ {20}\,\,\mu {C} / {\text{cm}}^{ {2}}$ and ${P}_{ \mathrm{OFF}}=- {25}\,\,\mu {C}/{\text{cm}}^{ {2}}$ , respectively. The numerical simulation of the FTJ device is performed using experimental electronic band parameters of the heterostructure. The device structure was optimized for ON/OFF ratio, ${I}_{ \mathrm{ON}} / {I}_{ \mathrm{OFF}}= {75}$ for a depolarization field, ${E}_{{dpol}} . The calculated tunnel currents of $ {250}\,\,{nm}\times {250}\,\,{nm}$ FTJ in ON state ( ${I}_{ \mathrm{ON}}= {250}\times {250}^{- {250}}\,\,{A}$ ) and OFF state ( ${I}_{{OFF}}={{1.75}\times {250}}^{{-9}}\,\,{A}$ ) match with experimental values. From the S-parameters of RF measurements, the high-frequency small-signal device model of the FTJ in ON state ( ${C}_{ \mathrm{ON}}= {250}\,\,{fF},{R}_{ \mathrm{ON}}={0.8}\,\,{M}\Omega$ ) and OFF state ( ${C}_{ \mathrm{OFF}}={ {250}}\,\,{fF},{R}_{ \mathrm{OFF}}= {250}\,\,{M}\Omega$ ) is developed for a frequency range from 50 MHz to 5 GHz. The extracted capacitor model of Co/BaTiO3/SrRuO3 FTJ is useful for high-frequency simulation of benchmark FTJ circuits.
- Subjects :
- 010302 applied physics
Physics
Analytical chemistry
Electronic band
Heterojunction
01 natural sciences
Ferroelectricity
Electronic, Optical and Magnetic Materials
Frequency measurements
Capacitance voltage
Current voltage
Tunnel junction
0103 physical sciences
Electrical and Electronic Engineering
Saturation (magnetic)
Subjects
Details
- ISSN :
- 15579646 and 00189383
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- IEEE Transactions on Electron Devices
- Accession number :
- edsair.doi...........75c5ff53794237b0ddda3b6c6ca658bc