Ferroelectric Properties of II-VI Type Semiconducting Thin Films on Si(100)

1999 ◽  
Vol 596 ◽  
Author(s):  
Y. Hotta ◽  
H. Tabata ◽  
T. Kawai
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Ferroelectric Films ◽  
Host Atom ◽  
Type Semiconductor ◽  
Electric Dipoles ◽  
Wide Gap ◽  
Ferroelectric Hysteresis ◽  
Semiconducting Thin Films ◽  
With Memory

AbstractWe have demonstrated the presence of ferroelectric properties in non-oxide (II-VI type semiconductor) ferroelectric thin films, such as (Zn,Cd)Te, (Zn,Cd)Se and (Zn,Cd)S (thickness: 3000–5000 Å). They have shown the ferroelectric hysteresis feature with memory windows of 0.2V, 0.3V and 0.8V, respectively. The materials design for getting the ferroelectric nature is as follows: when the size of the replaced atom is smaller than the host atom, then the substituent atoms can occupy off-centered positions, thus locally induce electric dipoles, thereby leading to ferroelectric behavior. These II-VI wide gap semiconducting ferroelectric films will open the door for new memory devices.

Influence of Excess Potassium on Structural and Ferroelectric Properties of Lead-Free Bi0.5K0.5TiO3 Thin Films

2021 ◽  
Vol 21 (4) ◽  
pp. 2681-2686
Author(s):  
Nguyen Ngoc Minh ◽  
Bui Van Dan ◽  
Nguyen Duc Minh ◽  
Guus Rijnders ◽  
Ngo Duc Quan
Keyword(s):  
Thin Films ◽  
Chemical Solution Deposition ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
Chemical Solution ◽  
Ferroelectric Films ◽  
Solution Deposition ◽  
Si Substrates ◽  
Excess Amount

Lead-free Bi0.5K0.5TiO3 (BKT) ferroelectric films were synthesized on Pt/Ti/SiO2/Si substrates via the chemical solution deposition. The influence of the excess potassium on the microstructures and the ferroelectric properties of the films was investigated in detail. The results showed that the BKT films have reached the well-crystallized state in the single-phase perovskite structure with 20 mol.% excess amount of potassium. For this film, the ferroelectric properties of the films were significantly enhanced. The remnant polarization (Pr) and maximum polarization (Pm) reached the highest values of 9.4 μC/cm2 and 32.2 μC/cm2, respectively, under the electric field of 400 kV/cm.

Structural and Ferroelectric Properties of Epitaxial PbZr0.52Ti0.48O3 and BaTiO3 Thin Films Prepared on SrRuO3/SrTiO3(100) Substrates

2001 ◽  
Vol 688 ◽  
Author(s):  
J. Rodríguez Contreras ◽  
J. Schubert ◽  
U. Poppe ◽  
O. Trithaveesak ◽  
K. Szot ◽  
...  
Keyword(s):  
Thin Films ◽  
Rutherford Backscattering Spectrometry ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Tunnel Current ◽  
Single Crystalline ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Ferroelectric Hysteresis

AbstractWe have prepared single crystalline epitaxial PbZr0.52Ti0.48O3 (PZT) and BaTiO3 (BTO) thin films on single crystalline epitaxial SrRuO3 (SRO) thin films grown on SrTiO3 (100) (STO) substrates. PZT and SRO thin films were grown using high-pressure on-axis sputtering and BTO using pulsed laser deposition (PLD). The film thickness ranged between 12 to 165 nm. Their excellent structural properties, surface smoothness and interface sharpness were demonstrated by X-Ray Diffraction measurements (XRD), High Resolution Transmission Electron Microscopy (HRTEM) and Atomic Force Microscopy (AFM). Rutherford Backscattering Spectrometry and Channeling measurements (RBS/C) were used to analyze stoichiometry and crystalline quality. Ferroelectric hysteresis loops were obtained for all films of a thickness down to 12 nm showing a decrease in the remanent polarization Pr and an increase in the coercive field Ec towards thinner film thicknesses. Furthermore we have prepared tunneling junctions with a PZT or BTO barrier thickness of 3-6 nm. Reproducible bi-stable I-V-curves and bias dependence of the conductance were obtained suggesting an influence of the ferroelectric properties of the barrier material on the tunnel current.

EFFECT OF PRE-HEATING TEMPERATURE ON THE CHARACTERISTICS OF PZT THIN FILMS GROWN BY USING A TRIOL SOL–GEL ROUTE

2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Heating Temperature ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Lead Zirconate ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
Ferroelectric Hysteresis

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.

Electrical Characteristics and Microstructures of Eu2O3-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 177 ◽  
pp. 197-200
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
K.L. Su ◽  
A.H. Cai ◽  
J. Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Differential Resistance ◽  
Rf Magnetron Sputtering ◽  
Electrical Characteristics ◽  
Si Substrates ◽  
Ferroelectric Hysteresis

Eu2O3-doped bismuth titanate (Bi1-xEuxTi3O12: BET) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BET films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with x=0.0 , 0.25, 1.0 and 1.25, I-E characteristics exhibited negative differential resistance behaviors and their ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with x=0.5 and 0.75, I-E characteristics were simple ohmic behaviors and their ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization (Pr) and coercive field (Ec) of the BET Film with x=0.75 were above 30μC/cm2 and 85KV/cm , respectively.

Ferroelectric Properties and Microstructures of Pr6O11-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 281-284
Author(s):  
Min Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
K.L. Su ◽  
Chong Qing Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Si Substrates ◽  
Large Leakage Current ◽  
Ferroelectric Hysteresis

Pr6O11-doped bismuth titanate (BixPryTi3O12: BPT) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BPT films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with y=0.06, 0.3, 1.2 and 1.5, ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with y=0.6 and 0.9, ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT Film with y=0.9 were above 35μC/cm2 and 80KV/cm , respectively. After 3×1010 switching cycles, 20% degradation of 2Pr is observed in the film with y=0.9.

Local Hysteresis Behavior of Ferroelectric Thin Films of Si added PbTiO3

2003 ◽  
Vol 784 ◽  
Author(s):  
V. R. Palkar ◽  
M. Higgins ◽  
S. C. Purandare ◽  
R. Pinto ◽  
S. Bhattacharya
Keyword(s):  
Thin Films ◽  
Grain Boundaries ◽  
Ferroelectric Properties ◽  
Ferroelectric Material ◽  
Laser Deposition ◽  
Si Substrate ◽  
Mole Percent ◽  
Hysteresis Behavior ◽  
The Matrix ◽  
Ferroelectric Hysteresis

ABSTRACTWe report ferroelectric properties and local hysteresis behavior of 2 mole percent Si added PbTiO3 thin films grown on Pt/TiO2/SiO2/Si substrate by using pulsed laser deposition technique. The ferroelectric hysteresis loop and scanning piezoresponce images obtained on these films by using AFM with conducting tip demonstrate excellent properties, which are equivalent to any other established ferroelectric material like PZT. Si segregating at the grain boundaries controls grain growth. The grain size and grain boundaries play a crucial role in determining ferroelectric hysteresis properties. The presence of Si in the matrix can be useful in tuning the properties.

Ferroelectric Properties of La-doped Bi4Ti3O12 Thin Films deposited directly on Si by pulse-injection MOCVD

2000 ◽  
Vol 655 ◽  
Author(s):  
Joon Hyeong Kim ◽  
Jin Young Kim ◽  
Hyeong Joon Kim
Keyword(s):  
Thin Films ◽  
Metalorganic Chemical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Low Frequency ◽  
Chemical Vapor ◽  
Amorphous Layer ◽  
Frequency Region ◽  
Pulse Injection ◽  
Ferroelectric Hysteresis ◽  
La Doped

Abstract(Bi,La)4Ti3O12(BLT) thin films were prepared on Si(100) substrates by the pulse injection metalorganic chemical vapor deposition (MOCVD) process, in which Ti and La precursors were injected with periodic pauses while Bi precursor was supplied continuously. In case of the pulse injection method, the film composition was relatively uniform and the Bi content at the interface was relatively uniform and the Bi content at the interface was increased. The BLT films, which were deposited by the pulse injection MOCVD, showed better crystallinity and thinner ionterfacial amorphous layer than the continuous BLT films. The continuous BLT films, although measured at 1 MHz showed similar C-V characteristics to those measured at low frequency region, and their flatband voltages also shifted severely to the negative voltage direction. On the other hand, the pulse BLT films exhibited clockwise ferroelectric hysteresis in the C-V curves. The memory window and the leakage current density were about 2V and 1.46×10−7 A/cm2 at 9V (180 kV/cm), respectively.

Ferroelectric Characteristics of SrxBi2.4Ta2O9 Thin Films and Electrical Properties of the Pt/SrxBi2.4Ta2O9/TiO2/Si Structure

2004 ◽  
Vol 449-452 ◽  
pp. 477-480
Author(s):  
J.H. Choi ◽  
Tae Sung Oh
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Coercive Field ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Memory Window ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Metalorganic Decomposition ◽  
Ferroelectric Hysteresis

Ferroelectric characteristics of the 400 nm-thick SrxBi2.4Ta2O9(0.7≤x≤1.3) thin films processed by metalorganic decomposition were investigated, and electrical properties of the Pt/Sr0.85Bi2.4Ta2O9/TiO2/Si structure prepared using TiO2 buffer layer were characterized. The Sr-deficient SrxBi2.4Ta2O9 films exhibited well-developed ferroelectric hysteresis curves compared to those of the Sr-excess films. The Sr0.85Bi2.4Ta2O9 film exhibited optimum ferroelectric properties, such as high remanent polarization and low leakage current density, among SrxBi2.4Ta2O9 films. A memory window of the Pt/SrxBi2.4Ta2O9/TiO2/Si structure was dependent upon the coercive field of the SrxBi2.4Ta2O9 film, and the Pt/SrxBi2.4Ta2O9/TiO2/Si exhibited a maximum memory window of 1.3 V at the sweeping voltage of ±5 V.

The effect of excess bismuth on the ferroelectric properties of SrBi2Ta2O9 thin films

1997 ◽  
Vol 12 (6) ◽  
pp. 1569-1575 ◽  
Author(s):  
Tze-Chiun Chen ◽  
Tingkai Li ◽  
Xubai Zhang ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Solid Solution ◽  
Grain Size ◽  
Leakage Current ◽  
Ferroelectric Properties ◽  
Substantial Improvement ◽  
Second Phase ◽  
Limited Solid Solution ◽  
Low Leakage ◽  
Ferroelectric Hysteresis

The effect of excess bismuth on the ferroelectric properties of SrBi2Ta2O9 (SBT) thin films having a perovskite-like layered structure was investigated for excess bismuth contents ranging from 0% to 100%. For the first time, a limited solid solution of SBT and Bi2O3 was shown to exist when the amount of excess Bi was less than 50%. The formation of a solid solution enhanced the grain size and a-b plane orientation of the films, resulting in substantial improvement in the ferroelectric hysteresis properties of the films. On the other hand, when the amount of excess Bi exceeded 50%, Bi2O3 appeared as a second phase which led to high leakage current and poor ferroelectric hysteresis curves. 30–50% excess Bi content was found to be the optimum composition with respect to grain size, crystallographic orientation, and single phase formation. Within this range, SBT films exhibit low leakage current density (˜10−9 A/cm2) and maximum remanent polarization (2Pr ˜12 µC/cm2).

scholarly journals Simple and Rapid Fabrication of Na0.5K0.5NbO3 Thin Films by a Chelate Route

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
A. Fernández Solarte ◽  
N. Pellegri ◽  
O. de Sanctis ◽  
M. G. Stachiotti
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Chelating Agent ◽  
Secondary Phase ◽  
Secondary Phases ◽  
Solution Synthesis ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Ferroelectric Hysteresis

Na0.5K0.5NbO3 (NKN) thin films were prepared by a chelate route which offers the advantage of a simple and rapid solution synthesis. The route is based on the use of acetoin as a chelating agent. The process was optimized by investigating the effects of alkaline volatilization on film properties. While we observed no evidence of stoichiometry problems due to potassium volatilization loss during the heat treatments, thin films synthesized with insufficient sodium excess presented a potassium-rich secondary phase, which has a significant influence on the ferroelectric properties. We show that the amount of spurious phase decreases with increasing Na+ concentration, in such a way that a 20 mol% Na+ excess is necessary to fully compensate the volatilization loss that occurred during the heat treatment. In this way, NKN thin films annealed at 650°C presented a well-crystallized perovskite structure, no secondary phases, well-defined ferroelectric hysteresis loops (Pr~9 μC/cm2, EC~45 kV/cm), and low leakage current density (2×10-7 A/cm2 at 80 kV/cm).

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