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Giant Dielectric Permittivity in Ferroelectric Thin Films: Domain Wall Ping Pong.

Quan Jiang A, Jian Meng X, Wei Zhang D, Hyuk Park M, Yoo S, Jin Kim Y, Scott JF, Seong Hwang C - Sci Rep (2015)

Bottom Line: The dielectric permittivity in ferroelectric thin films is generally orders of magnitude smaller than in their bulk.Here, we discover a way of increasing dielectric constants in ferroelectric thin films by ca. 500% by synchronizing the pulsed switching fields with the intrinsic switching time (nucleation of domain plus forward growth from cathode to anode).This permits smaller capacitors in memory devices and is a step forward in making ferroelectric domain-engineered nano-electronics.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of ASIC &System, School of Microelectronics, Fudan University, Shanghai 200433, China.

ABSTRACT
The dielectric permittivity in ferroelectric thin films is generally orders of magnitude smaller than in their bulk. Here, we discover a way of increasing dielectric constants in ferroelectric thin films by ca. 500% by synchronizing the pulsed switching fields with the intrinsic switching time (nucleation of domain plus forward growth from cathode to anode). In a 170-nm lead zirconate titanate thin film with an average grain size of 850 nm this produces a dielectric constant of 8200 with the maximum nucleus density of 3.8 μm(-2), which is one to three orders of magnitude higher than in other dielectric thin films. This permits smaller capacitors in memory devices and is a step forward in making ferroelectric domain-engineered nano-electronics.

No MeSH data available.


The closed and open symbols show the switching current density as a function of the inverse coercive field of the PZT in capacitors with different sizes for the forward expansion and sideways wall motion of the nucleating domains, respectively.The data can be fitted by a red solid line, according to Merz’s law. The black solid line shows the domain expansion time as a function of the current density for the nucleating domains to touch the opposite electrode.
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f2: The closed and open symbols show the switching current density as a function of the inverse coercive field of the PZT in capacitors with different sizes for the forward expansion and sideways wall motion of the nucleating domains, respectively.The data can be fitted by a red solid line, according to Merz’s law. The black solid line shows the domain expansion time as a function of the current density for the nucleating domains to touch the opposite electrode.

Mentions: J was measured as a function of inverse of coercive field , and the results for the capacitors with various sizes are summarized in Fig. 2. For this work, Pt/Pb(Zr0.4Ti0.6)O3(PZT)/Pt polycrystalline thin film capacitors with a 170-nm PZT thickness and an average PZT grain size of ~800 nm were deposited on TiOx/SiO2/Si substrates (on-line SI Part D: Fig. S8a) using a sol-gel processing technique. Then the films were patterned into discrete square capacitors (see Methods). The data in Fig. 2 are well described by Merz’s exponential law6, , as shown by the (red) solid line. The fitting of the experimental data to Merz’s law gave an activation field Ea = 2.0 MV/cm, which is consistent with a previous report27. From the result /Pnu/ = 4.1 μC/cm2, which will be discussed in detail below, Δt can be calculated, as shown by the (black) solid line in Fig. 2 using Eq. (2). This is the approximate time for the nucleating domains to touch the opposite electrode at each J (or V).


Giant Dielectric Permittivity in Ferroelectric Thin Films: Domain Wall Ping Pong.

Quan Jiang A, Jian Meng X, Wei Zhang D, Hyuk Park M, Yoo S, Jin Kim Y, Scott JF, Seong Hwang C - Sci Rep (2015)

The closed and open symbols show the switching current density as a function of the inverse coercive field of the PZT in capacitors with different sizes for the forward expansion and sideways wall motion of the nucleating domains, respectively.The data can be fitted by a red solid line, according to Merz’s law. The black solid line shows the domain expansion time as a function of the current density for the nucleating domains to touch the opposite electrode.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594126&req=5

f2: The closed and open symbols show the switching current density as a function of the inverse coercive field of the PZT in capacitors with different sizes for the forward expansion and sideways wall motion of the nucleating domains, respectively.The data can be fitted by a red solid line, according to Merz’s law. The black solid line shows the domain expansion time as a function of the current density for the nucleating domains to touch the opposite electrode.
Mentions: J was measured as a function of inverse of coercive field , and the results for the capacitors with various sizes are summarized in Fig. 2. For this work, Pt/Pb(Zr0.4Ti0.6)O3(PZT)/Pt polycrystalline thin film capacitors with a 170-nm PZT thickness and an average PZT grain size of ~800 nm were deposited on TiOx/SiO2/Si substrates (on-line SI Part D: Fig. S8a) using a sol-gel processing technique. Then the films were patterned into discrete square capacitors (see Methods). The data in Fig. 2 are well described by Merz’s exponential law6, , as shown by the (red) solid line. The fitting of the experimental data to Merz’s law gave an activation field Ea = 2.0 MV/cm, which is consistent with a previous report27. From the result /Pnu/ = 4.1 μC/cm2, which will be discussed in detail below, Δt can be calculated, as shown by the (black) solid line in Fig. 2 using Eq. (2). This is the approximate time for the nucleating domains to touch the opposite electrode at each J (or V).

Bottom Line: The dielectric permittivity in ferroelectric thin films is generally orders of magnitude smaller than in their bulk.Here, we discover a way of increasing dielectric constants in ferroelectric thin films by ca. 500% by synchronizing the pulsed switching fields with the intrinsic switching time (nucleation of domain plus forward growth from cathode to anode).This permits smaller capacitors in memory devices and is a step forward in making ferroelectric domain-engineered nano-electronics.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of ASIC &System, School of Microelectronics, Fudan University, Shanghai 200433, China.

ABSTRACT
The dielectric permittivity in ferroelectric thin films is generally orders of magnitude smaller than in their bulk. Here, we discover a way of increasing dielectric constants in ferroelectric thin films by ca. 500% by synchronizing the pulsed switching fields with the intrinsic switching time (nucleation of domain plus forward growth from cathode to anode). In a 170-nm lead zirconate titanate thin film with an average grain size of 850 nm this produces a dielectric constant of 8200 with the maximum nucleus density of 3.8 μm(-2), which is one to three orders of magnitude higher than in other dielectric thin films. This permits smaller capacitors in memory devices and is a step forward in making ferroelectric domain-engineered nano-electronics.

No MeSH data available.