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 Properties of a-Axis Textured BaTiO3 Thin Films

1993 ◽  
Vol 310 ◽  
Author(s):  
H. A. Lu ◽  
L. A. Wills ◽  
B. W. Wessels ◽  
X. Zhan ◽  
J. A. Helfrich ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Dielectric Properties ◽  
Electric Field ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Chemical Vapor ◽  
Ferroelectric Hysteresis ◽  
Metalorganic Chemical

AbstractFerroelectric and dielectric properties were measured for BaTiO3 thin films prepared by metalorganic chemical vapor deposition which were highly a-axis textured. No ferroelectric hysteresis was observed from the as-deposited BaTiO3 films on Pt coated MgO. Upon applying an electric field exceeding a threshold electric field, Et, ∼ 50 - 100 kV/cm, a ferroelectric hysteresis was observed. A spontaneous polarization Ps ≥ 15 μC/cm2 was measured for the textured films.

Ferroelectric properties of lanthanide-substituted Bi4Ti3O12 epitaxial thin films grown by metalorganic chemical vapor deposition

2003 ◽  
Vol 93 (3) ◽  
pp. 1707-1712 ◽  
Author(s):  
Takashi Kojima ◽  
Takayuki Watanabe ◽  
Hiroshi Funakubo ◽  
Keisuke Saito ◽  
Minoru Osada ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Chemical Vapor ◽  
Epitaxial Thin Films ◽  
Metalorganic Chemical

Metalorganic chemical vapor deposition of very thin Pb(Zr,Ti)O3 thin films at low temperatures for high-density ferroelectric memory applications

2001 ◽  
Vol 16 (12) ◽  
pp. 3583-3591 ◽  
Author(s):  
Hye Ryoung Kim ◽  
Seehwa Jeong ◽  
Chung Bae Jeon ◽  
Oh Seong Kwon ◽  
Cheol Seong Hwang ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Ferroelectric Properties ◽  
Chemical Vapor ◽  
High Density ◽  
Pt Electrode ◽  
Ferroelectric Memory ◽  
Metalorganic Chemical

The metalorganic chemical vapor deposition of very thin (<50 nm) Pb(Zr,Ti)O3 (PZT) thin films was performed for high density (>32 mega bit) ferroelectric memory devices. The growth temperatures were set between 450 and 530 °C to obtain a smooth surface morphology and prevent damage to the underlying reaction barrier layer. The average grain size of a 50-nm-thick film on a Pt electrode was about 34 nm with a size distribution (σ2) of 11 nm. These values are much smaller than the sol-gel-derived PZT films (55 and 25 nm, respectively). Very thin films with a thickness of approximately 30 nm were prepared at wafer temperatures ranging from 500 to 525 °C. Even with the very small thickness, the films showed good ferroelectric properties with a typical remanent polarization from 10 to 15 μC/cm2 and an extremely low coercive voltage of 0.3 V. However, the leakage current density was rather high resulting in nonsaturating polarization versus voltage curves. Even though good ferroelectric properties were obtained, the formation of PtxPby alloys on top of the Pt electrode was consistently observed. This precludes the reliable control of film composition and electrical performance. The adoption of an Ir electrode successfully eliminated intermetallic alloy formation and resulted in better and reproducible process control. A 50-nm-thick PZT film on an Ir/IrO2/SiO2/Si substrate also showed a reasonable ferroelectric performance.

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