A Study on the Growth of a Ferroelectric Thin Film Using Ionized Cluster Beam Epitaxy Technique and the Application for Ulsi Fabrication

1996 ◽  
Vol 441 ◽  
Author(s):  
Hyun Seok Lee ◽  
Man Young Sung
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Electron Beam ◽  
Dielectric Properties ◽  
Substrate Temperature ◽  
Ferroelectric Thin Film ◽  
Process Conditions ◽  
Cluster Beam ◽  
Bst Films ◽  
Ulsi Fabrication

AbstractThe dielectric properties of Ba0.65Sr0.35TiO3(BST) films deposited by an electron beam assisted ionized cluster beam epitaxy (ICBE) technique were investigated. Highly (110) oriented BST films having a thickness up to 1, um have been successfully grown on a Si (100) substrate at 400°C using the electron beam assisted ICBE system with a plasma O2 source. It was found that the dielectric constant increases from 475 to 1191 with different process conditions. A BST film with a thickness of 500Å deposited at a substrate temperature of 400°C has a dielectric constant of 1191 and a leakage current of about 2.37×10-9 A/cm2. This shows the BST film can be applied to dielectrics of ULSI capacitors.

The effects of PBB on the dielectric properties of BST film

2005 ◽  
Vol 902 ◽  
Author(s):  
Jin Cheol Kim ◽  
Jun Rok Oh
Keyword(s):  
Thin Film ◽  
Heat Treatment ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Magnetron Sputtering ◽  
Metal Oxide ◽  
Current Density ◽  
Energy Dispersive Spectrometer ◽  
Ferroelectric Thin Film ◽  
Rf Magnetron Sputtering

AbstractThe mixture of PbO-Bi2O3-B2O3 (PBB) were formed on the Ba0.5Sr0.5TiO3 (BST) film and the effects of PBB phase on the dielectric properties of the BST film were investigated. The amorphous PBB layer was deposited on the BST film using rf magnetron sputtering and diffused into the film by heat treatment. The PBB phase in BST film was identified by energy dispersive spectrometer (EDS). Dielectric properties of BST film were significantly improved after the diffusion of PBB. The leakage current density of BST film decreased from 3.24×10-5 A/cm2 to 9.45×10-8 A/cm2 at 1.5 V and the dielectric constant increased from 238 to 533. These results show that the diffusion of insulating metal oxide into the ferroelectric thin film can improve the dielectric properties of the film.

Substrate-induced mechanical and dielectric properties of a ferroelectric thin film

2002 ◽  
Vol 91 (8) ◽  
pp. 4973-4982 ◽  
Author(s):  
L. Lahoche ◽  
V. Lorman ◽  
S. B. Rochal ◽  
J. M. Roelandt
Keyword(s):  
Thin Film ◽  
Dielectric Properties ◽  
Ferroelectric Thin Film

scholarly journals Impact of process conditions on chemical solution deposited BNKT thin film electromechanical properties

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Kyle M. Grove ◽  
Austin Fox ◽  
David P. Cann ◽  
Song Won Ko ◽  
Peter Mardilovich ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Pyrolysis Temperature ◽  
Piezoelectric Response ◽  
Excess Properties ◽  
Process Conditions ◽  
Chemical Solution ◽  
Ramp Rate

Abstract Phase pure perovskite (1-x)Bi1/2Na1/2TiO3 – xBi1/2K1/2TiO3 (BNKT) thin films were successfully prepared via an inverse mixing order chemical solution deposition method and the impact of process conditions on film properties were observed. Process conditions evaluated included crystallization temperature and time, ramp rate, pyrolysis temperature, and cation excess. Properties measured included crystal structure, dielectric constant, dielectric loss, piezoelectric response, and ferroelectric response. A few notable trends were observed. A subtle impact on piezoelectric response was observed in films prepared using different ramp rates: 100 C per second films (d33,f = 60 ± 5 pm/V at 1 kHz), 75 °C per second films (d33,f = 55 ± 5 pm/V) and 150 C per second films (d33,f = 50 ± 5 pm/V). Films prepared using a 75 °C per second ramp rate displayed slightly higher dielectric loss (tan δ = 0.09 at 1 kHz) than films prepared using a 100 °C per second ramp rate (tan δ = 0.07 at 1 kHz) or 150 °C per second ramp rate (tan δ = 0.05 at 1 kHz). Pyrolysis temperatures greater than 350 °C are necessary to burn off organics and maximize film dielectric constant. Dielectric constant increased from 450 ± 50 at 1 kHz to 600 ± 50 at 1 kHz by increasing pyrolysis temperature from 300 to 400 °C. Excess cation amounts (for compositional control) were also evaluated and it was found films with higher amounts of Na and K excess compared to bismuth excess displayed an increase in d33,f of about 10 pm/V compared to films prepared with equivalent Bi and Na and K excess amounts. Article highlights Impact of processing conditions on inverse mixing order chemical solution deposited bismuth based thin films. Dielectric, piezoelectric, and ferroelectric properties of thin film bismuth sodium titanate-bismuth potassium titanate thin films. Developing lead-free piezoelectric actuator materials.

Low-temperature fabrication of high-quality (Ba, Sr)TiO3 films using charged liquid cluster beam method

2002 ◽  
Vol 17 (8) ◽  
pp. 1888-1891 ◽  
Author(s):  
Hyungsoo Choi ◽  
Sungho Park ◽  
Yi Yang ◽  
HoChul Kang ◽  
Kyekyoon (Kevin) Kim ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Low Temperature ◽  
Cluster Beam ◽  
High Quality ◽  
Carboxylate Ligands ◽  
Si Substrates ◽  
Beam Method ◽  
Temperature Deposition ◽  
Bst Films ◽  
Substrate Temperatures

Low-temperature deposition of high-quality (Ba, Sr)TiO3 (BST) thin films was achieved in air on Pt/Ti/SiO2/Si substrates using the charged liquid cluster beam (CLCB) method. The Ba, Sr, and Ti precursors were synthesized using alkoxy carboxylate ligands to tailor their physical properties to the CLCB process. The as-deposited BST films fabricated at substrate temperatures as low as 280 °C exhibited high purity. The leakage current density and dielectric constant of the film, deposited at 300 °C and subsequently annealed at 700 °C, were 2.5 × 10−9 A/cm2 at 1.5 V and 305, respectively.

Pulsed Laser Deposition of BaxSr1−xTiO3 Films on MgO, LaAlO3 and SrTiO3 for Tunable Microwave Applications

1998 ◽  
Vol 541 ◽  
Author(s):  
Wontae Chang ◽  
James S. Horwitz ◽  
Won-Jeong Kim ◽  
Jeffrey M. Pond ◽  
Steven W. Kirchoefer ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electric Field ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Dielectric Constants ◽  
Laser Deposition ◽  
Film Stress ◽  
Donor Acceptor ◽  
Bst Films

AbstractSingle phase BaxSr1−xTiO3 (BST) films (∼0.5-7 μm thick) have been deposited onto single crystal substrates (MgO, LaAlO3, SrTiO3) by pulsed laser deposition. Silver interdigitated electrodes were deposited on top of the ferroelectric film. The room temperature capacitance and dielectric Q (1/tanδ) of the film have been measured as a function of electric field (≤80 kV/cm) at 1 - 20 GHz. The dielectric properties of the film are observed to strongly depend on substrate type and post-deposition processing. After annealing (≤1000° C), it was observed that the dielectric constant and % tuning decreased and the dielectric Q increased for films deposited onto MgO, and the opposite effect was observed for films deposited onto LaA1O3. Presumably, this change in dielectric properties is due to the changes in film stress. Very thin (∼50 Å) amorphous BST films were successfully used as a stress-relief layer for the subsequently deposited crystalline BST (∼5000 Å) films to maximize % tuning and dielectric Q. Films have been deposited from stoichiometric targets and targets that have excess Ba and Sr. The additional Ba and Sr has been added to the target to compensate for deficiencies in Ba and Sr observed in the deposited BST (x=0.5) films. Films deposited from compensated targets have higher dielectric constants than films deposited from stoichiometric targets. Donor/acceptor dopants have also been added to the BST target (Mn, W, Fe ≤4 mol.%) to further improve the dielectric properties. The relationship between the dielectric constant, the dielectric Q, the change in dielectric constant with electric field is discussed.

Experimental and Theoretical Investigation into the Dielectric Behaviour of Ferroelectric Thin Film Superlattices

2000 ◽  
Vol 656 ◽  
Author(s):  
J. M. Gregg ◽  
D. O'Neill ◽  
G. Catalan ◽  
R. M. Bowman
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Carrier Mobility ◽  
Ferroelectric Thin Film ◽  
Loss Analysis ◽  
High Dielectric Loss ◽  
Unit Cells ◽  
Dielectric Enhancement ◽  
Frequency Relaxation ◽  
High Dielectric

ABSTRACTPulsed laser deposition has been used to fabricate thin-film capacitor structures in which the dielectric layer is composed of a superlattice of Ba0.8Sr0.2TiO3 and Ba0.2Sr0.8TiO3. The properties of the capacitors were investigated as a function of superlattice periodicity. The dielectric constant was significantly enhanced, and temperature migration of the peak in dielectric constant as a function of frequency was observed, at stacking periodicities of a few unit cells. However, such “relaxor-like’ features were found to be associated with high dielectric loss. Analysis of the imaginary permittivity as a function of frequency showed that fine-scale superlattices conform to Maxwell-Wagner behaviour, indicating that the observed features may be an artefact of increased carrier mobility. Modelling showed that both dielectric enhancement and frequency relaxation could readily be reproduced by Maxwell-Wagner formalism.

Interface Structure and Dielectric Properties of SrTiO3 Thin Film Sputter-Deposited onto Si Substrates

1990 ◽  
Vol 200 ◽  
Author(s):  
S. Matsubara ◽  
T. Sakuma ◽  
S. Yamamichi ◽  
H. Yamaguchi ◽  
Y. Miyasaka
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Film Thickness ◽  
Noble Metals ◽  
Film Surface ◽  
Cross Sectional ◽  
Capacitance Density ◽  
Barrier Layers ◽  
Si Substrates

ABSTRACTSrTiO3 thin film preparation onto Si substrates using RF magnetron sputtering has been studied for a high capacitance density required for the next generation of LSI's. Structural and chemical analysis on the interface between SrTiO3 film and Si was carried out with cross-sectional TEM, EDX, and AES. Dielectric properties were measured on AuTi/SrTiO3/Si/Ti/Au capacitors. The as-grown dielectric films on Si were analyzed and found to consist of three layers; SiO2, amorphous SrTiO3 and crystalline SrTiO3, from interface toward film surface. By annealing at 600 °C, the amorphous SrTiO3 layer was recrystallized, and consequently the capacitance value increased. A typical specific capacitance was 4.7 fF/μm2 and the leakage current was in the order of 10−8 A/cm2, for 180 nm thick SrTiO3 film. The dielectric constant decreased from 147 to 56 with decreasing SrTiO3 film thickness from 480 nm to 80 nm. This is due to the low dielectric constant SiO2 layer (ε=3.9) at the interface. From the film thickness dependence of the ε value, the SiO2 layer thickness was calculated to be 3.9 nm, which agreed well with the value directly observed in the TEM.To avoid SiO2 layer formation, barrier layers between SrTiO3 and Si have been studied. Among various refractory and noble metals, RuSi and a multi-layer of Pt/Ti have been found to be promising candidates for the barrier material. When RuSi film or Pt/Ti film was formed between SrTiO3 film and Si substrate, dielectric constant of about 190 was obtained in dependent of the SrTiO3 film thickness in the range of 80–250 nm. Analysis on the barrier layers was performed by means of RBS, XPS and XRD.

STRUCTURAL AND DIELECTRIC PROPERTIES OF Ba0.5Sr0.5TiO3 THIN FILMS GROWN ON LAO WITH HOMO-EPITAXIAL LAYER FOR TUNABLE APPLICATIONS

2004 ◽  
Vol 18 (15) ◽  
pp. 2153-2168 ◽  
Author(s):  
M. CHANDRA SEKHAR
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Interfacial Layer ◽  
Ferroelectric Properties ◽  
Buffer Layers ◽  
High Tunability ◽  
Low Leakage ◽  
Structural Growth ◽  
Bst Films ◽  
Dielectric Devices

The epitaxial, single phase (100) Ba 0.5 Sr 0.5 TiO 3 (BST) films with thin interfacial layer of BST (x=0.4) were deposited on LAO (100) substrates using Pulse Laser Deposition (PLD). These films were characterized in terms of their phase formation and structural growth characteristics using X-ray diffraction and Atomic Force Microscopy respectively. The dielectric properties are strongly affected by the substrate type, post deposition annealing time, and temperature. In order to verify all these properties, thin interfacial-buffer layers of BST (10, 20, 50 nm) were introduced to relieve the stress induced between the film and the substrate. The variations of dielectric constant and ferroelectric properties of as deposited films are discussed in detail. The high tunability, low dielectric loss and low leakage current of these films make them attractive candidates for fabricating tunable dielectric devices. The observed dielectric properties of the BST-films are attributed to homo-epitaxial interfacial layer, which is responsible for the increase in the dielectric constant and tunability.

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