scholarly journals Strong interaction between ferroelectric polarization and oxygen vacancy in BiFeO3 thin film capacitors

2016 ◽  
Vol 124 (6) ◽  
pp. 634-638 ◽  
Author(s):  
Hiroki MATSUO ◽  
Yuuki KITANAKA ◽  
Yuji NOGUCHI ◽  
Masaru MIYAYAMA
Keyword(s):  
Thin Film ◽  
Oxygen Vacancy ◽  
Strong Interaction ◽  
Ferroelectric Polarization ◽  
Thin Film Capacitors

scholarly journals Synchrotron X-ray Microdiffraction Images of Polarization Switching in Epitaxial PZT Capacitors with Pt and SrRuO3 Top Electrodes

2003 ◽  
Vol 784 ◽  
Author(s):  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Eric M. Dufresne ◽  
Eric D. Isaacs ◽  
...  
Keyword(s):  
Thin Film ◽  
Bottom Electrode ◽  
Sputter Deposition ◽  
Ferroelectric Polarization ◽  
X Rays ◽  
X Ray ◽  
Pzt Film ◽  
Thin Film Capacitors ◽  
Pzt Thin Film ◽  
Switchable Polarization

ABSTRACTThe evolution of stored ferroelectric polarization in PZT thin film capacitors was imaged using synchrotron x-ray microdiffraction with a submicron-diameter focused incident x-ray beam. To form the capacitors, an epitaxial Pb(Zr,Ti)O3 (PZT) thin film was deposited on an epitaxially-grown conductive SrRuO3 (SRO) bottom electrode on a SrTiO3 (STO) (001) substrate. Polycrystalline SRO or Pt top electrodes were prepared by sputter deposition through a shadow mask and subsequent annealing. The intensity of x-ray reflections from the PZT film depended on the local ferroelectric polarization. With 10 keV x-rays, regions of opposite polarization differed in intensity by 26% in our PZT capacitor with an SRO top electrode. Devices with SRO electrodes showed just a 25% decrease in the remnant polarization after 107 switching cycles. In devices with Pt top electrodes, however, the switchable polarization decreased a by 70% after only 5×104 cycles.

scholarly journals Improved Negative Bias Stress Stability of Sol–Gel-Processed Li-Doped SnO2 Thin-Film Transistors

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1629
Author(s):  
Hyeon-Joong Kim ◽  
Do-Won Kim ◽  
Won-Yong Lee ◽  
Sin-Hyung Lee ◽  
Jin-Hyuk Bae ◽  
...  
Keyword(s):  
Thin Film ◽  
Oxygen Vacancy ◽  
Thin Film Transistors ◽  
Sol Gel ◽  
Sno2 Thin Film ◽  
Negative Bias ◽  
Semiconductor Films ◽  
Saturation Regime ◽  
Si Substrates ◽  
Ionic Size

In this study, sol–gel-processed Li-doped SnO2-based thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The influence of Li dopant (wt%) on the structural, chemical, optical, and electrical characteristics was investigated. By adding 0.5 wt% Li dopant, the oxygen vacancy formation process was successfully suppressed. Its smaller ionic size and strong bonding strength made it possible for Li to work as an oxygen vacancy suppressor. The fabricated TFTs consisting of 0.5 wt% Li-doped SnO2 semiconductor films delivered the field-effect mobility in a 2.0 cm2/Vs saturation regime and Ion/Ioff value of 1 × 108 and showed enhancement mode operation. The decreased oxygen vacancy inside SnO2 TFTs with 0.5 wt% Li dopant improved the negative bias stability of TFTs.

Investigation of Dead Layer Thickness in SrRuO3/Ba0.5Sr0.5TiO3/Au Thin Film Capacitors

2000 ◽  
Vol 655 ◽  
Author(s):  
L. J. Sinnamon ◽  
R. M. Bowman ◽  
J. M. Gregg
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Layer Thickness ◽  
Perovskite Phase ◽  
Frequency Dispersion ◽  
Dead Layer ◽  
Parameter Ratio ◽  
Thin Film Capacitors ◽  
Dead Layer Thickness ◽  
The Dead

AbstractThin film capacitors with barium strontium titanate (BST) dielectric layers of 7.5 to 950 nm were fabricated by Pulsed Laser Deposition. XRD and EDX analyses confirmed a strongly oriented BST cubic perovskite phase with the desired cation stoichiometry. Room temperature frequency dispersion (ε100 kHz / ε100 Hz) for all capacitors was greater than 0.75. Absolute values for the dielectric constant were slightly lower than expected. This was attributed to the use of Au top electrodes since the same sample showed up to a threefold increase in dielectric constant when Pt was used in place of Au. Dielectric constant as a function of thicknesses greater than 70 nm, was fitted using the series capacitor model. The large interfacial parameter ratio di / εi of 0.40 ± 0.05 nm implied a significant dead-layer component within the capacitor structure. Modelled consideration of the dielectric behaviour for BST films, whose total thickness was below that of the dead layer, predicted anomalies in the plots of d/ ε against d at the dead layer thickness. For the SRO/BST/Au system studied, no anomaly was observed. Therefore, either (i) 7.5 nm is an upper limit for the total dead layer thickness in this system, or (ii) dielectric collapse is not associated with a distinct interfacial dead layer, and is instead due to a through-film effect.

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