The Effect of Hydrolysis Conditions on the Characteristics of PbTiO3 Gels and Thin Films

1986 ◽  
Vol 72 ◽  
Author(s):  
K. D. Budd ◽  
S. K. Dey ◽  
D. A. Payne
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Electronic Ceramics ◽  
Base Catalysts ◽  
Acid And Base ◽  
Crystalline Films ◽  
Continuous Crack ◽  
Free Films ◽  
Hydrolysis Conditions

AbstractSol-gel processing represents a promising method of fabrication for thin films of electronic ceramics which are useful in a number of packaging and device applications. In this study, the influence of acid and base catalysts on the structure of PbTiO3 gels and films (0.1-1.0μm) was investigated, for the purpose of inducing and identifying gel structures which were the most suitable as precursors for thin dielectric layers. Continuous, crack-free films, with dielectric strengths in excess of 106 V/cm were developed. Basic solutions gelled rapidly, phase separated, and were probably more crosslinked than acidic gels. Acidic gels seemed more capable of polymeric rearrangement during drying, yielding denser amorphous structures with microcrystalline regions. High-field dielectric constants (1 MV/m ac) in the range K=30–40, and K=160–170, were determined for amorphous and crystalline films, respectively.

The Effect Of Hydrolysis Conditions On The Characteristics Of PbTiO3 Gels And Thin Films

1986 ◽  
Vol 73 ◽  
Author(s):  
K. D. Budd ◽  
S. K. Dey ◽  
D. A. Payne
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Electronic Ceramics ◽  
Base Catalysts ◽  
Acid And Base ◽  
Crystalline Films ◽  
Continuous Crack ◽  
Free Films ◽  
Hydrolysis Conditions

ABSTRACTSol-gel processing represents a promising method of fabrication for thin films of electronic ceramics which are useful in a number of packaging and device applications. In this study, the influence of acid and base catalysts on the structure of PbTiO3 gels and films (0.1–1.0 μm) was investigated, for the purpose of inducing and identifying gel structures which were the most suitable as precursors for thin dielectric layer. Continuous, crack-free films, with dielectric strengths in excess of 106 V/cm were developed. Basic solutions gelled rapidly, phase separated, and were probably more crosslinked than acidic gels. Acidic gels seemed more capable of polymeric rearrangement during drying, yielding denser amorphous structures with microcrystalline regions. High-field dielectric constants (1 MV/m ac) in the range K=30–40 and K=160–170, were determined for amorphous and crystalline films, respectively.

Microstructural characterization of sol-gel derived PbTiO3 thin films

1986 ◽  
Vol 44 ◽  
pp. 836-837
Author(s):  
K. D. Budd ◽  
S. K. Dey ◽  
D. A. Payne
Keyword(s):  
Thin Films ◽  
Structural Control ◽  
Sol Gel ◽  
Microstructural Characterization ◽  
Condensation Polymerization ◽  
Ceramic Films ◽  
Continuous Crack ◽  
Pyrolysis Behaviour ◽  
Hydrolysis Conditions ◽  
Alkoxy Groups

A process has been developed for the fabrication of continuous, crack-free layers, of a series of compositions in the PbO-La2O3-TiO2-ZrO2 system. These layers were formed by spin-casting solutions of complex alkoxides onto platinum, silicon, silica, and a variety of substrates. The dried layers were amorphous gels which could be densified and converted to ceramic films at relatively low temperatures (e.g., 350-500°C). Gellation was caused by the condensation polymerization of alkoxide molecules, and was initiated by hydrolysis of the alkoxy groups. Gel structures were manipulated by controlling hydrolysis conditions (catalyst and amount of water) in an effort to control pyrolysis behaviour, optimize microstructures, and minimize firing temperatures. Lower processing temperatures increased the compatibility with substrates such as Si wafers. Structural control was possible because the polymerization reactions become site-specific under certain hydrolysis conditions. As discussed below, microstructures of thin films were influenced considerably by both the type of catalyst, and by interactions with silicon substrates.

Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

2008 ◽  
Vol 368-372 ◽  
pp. 1817-1819
Author(s):  
Cui Hua Zhao ◽  
Bo Ping Zhang ◽  
Yong Liu ◽  
Song Jie Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Co Doping ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Coating Method ◽  
High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

SPECTROSCOPIC ELLIPSOMETRY INVESTIGATION ON OPTICAL PROPERTIES OF Fe:SNO2 THIN FILMS: EFFECTS OF IRON CONCENTRATION

2020 ◽  
pp. 2050044
Author(s):  
SAHAR MORADI ◽  
HASSAN SEDGHI
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Sol Gel ◽  
Iron Concentration ◽  
Dielectric Constants ◽  
Bandgap Energy ◽  
Dispersion Parameters ◽  
Glass Substrates ◽  
Coating Method

Nanostructured Fe:SnO2 thin films were deposited on glass substrates through sol–gel spin coating method. Films were synthesized with different iron quantities including 0%, 4%, 8% and 12% (wt.%). The effects of Fe concentration on optical properties of films were investigated by spectroscopic ellipsometry (SE) technique. SE measured ([Formula: see text]) parameters for films in the wavelength range between 300[Formula: see text]nm to 800[Formula: see text]nm. Optical properties including the refractive index, extinction coefficient, transmittance, dielectric constants and optical conductivity were determined by fitting the SE measured ([Formula: see text]) parameters and data obtained from the optical model-based analysis. Results showed that the transmittance values increase by increment of Fe concentration from 0% to 12%. The bandgap energy ([Formula: see text] of prepared thin films was also calculated. [Formula: see text] values were between 3.44 and 3.58[Formula: see text]eV. Dispersion parameters including the high frequency dielectric constant ([Formula: see text] and the ratio of free carrier concentration to effective mass (N/m[Formula: see text] were then obtained for the prepared films.

Microstructure and Crystallization Behavior of Sol-Gel Prepared BaTiO3 Thin Films

1994 ◽  
Vol 346 ◽  
Author(s):  
M.C. Gust ◽  
L.A. Momoda ◽  
M.L. Mecartney
Keyword(s):  
Thin Films ◽  
Crystallization Behavior ◽  
Sol Gel ◽  
Heat Treating ◽  
Furnace Annealing ◽  
Si Substrates ◽  
Fine Grain ◽  
Conventional Furnace ◽  
Final Microstructure ◽  
Hydrolysis Conditions

ABSTRACTThin films of BaTiO3 were prepared by the sol-gel route using barium titanium methoxypropoxide in methoxypropanol. Sols with water of hydrolysis varying between h=0 and h=2 were spun onto (100) Si and Ge coated (100) Si substrates. XRD and analytical TEM were used to study the microstructure and crystallization behavior of these films. Polycrystalline BaTiO3 was obtained by heat treating the films at temperatures between 600 and 750°C using either conventional furnace annealing or rapid thermal annealing. Films prepared from sols having the highest water content tended to crystallize first. The BaTiO3 thin films exhibited a fine grain size on the order of 25–50 nm. No preferred orientation was observed. The effects of the hydrolysis conditions of the sol, the type of heat treatment, and the choice of substrate on the final microstructure of the films are discussed.

Phase Transformations in Sol-Gel PZT Thin Films

2000 ◽  
Vol 623 ◽  
Author(s):  
D.P. Eakin ◽  
M.G. Norton ◽  
D.F. Bahr
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Room Temperature ◽  
Structural Changes ◽  
Sol Gel ◽  
Ex Situ ◽  
Ambient Conditions ◽  
Crystalline Films ◽  
In Situ Heating

AbstractThin films of PZT were deposited onto platinized and bare single crystal NaCl using spin coating and sol-gel precursors. These films were then analyzed using in situ heating in a transmission electron microscope. The results of in situ heating are compared with those of an ex situ heat treatment in a standard furnace, mimicking the heat treatment given to entire wafers of these materials for use in MEMS and ferroelectric applications. Films are shown to transform from amorphous to nanocrystalline over the course of days when held at room temperature. While chemical variations are found between films crystallized in ambient conditions and films crystallized in the vacuum conditions of the microscope, the resulting crystal structures appear to be insensitive to these differences. Significant changes in crystal structure are found at 500°C, primarily the change from largely amorphous to the beginnings of clearly crystalline films. Crystallization does occur over the course of weeks at room temperature in these films. Structural changes are more modest in these films when heated in the TEM then those observed on actual wafers. The presence of Pt significantly influences both the resulting structure and morphology in both in situ and ex situ heated films. Without Pt present, the films appear to form small, 10 nm grains consisting of both cubic and tetragonal phases, whereas in the case of the Pt larger, 100 nm grains of a tetragonal phase are formed.

Rapid Thermal Processing of Ferroelectric Thin Films

1991 ◽  
Vol 224 ◽  
Author(s):  
Zheng Wu ◽  
Roberto Pascual ◽  
C.V.R. Vasant Kumar ◽  
David Amd ◽  
Michael Sayer
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Thermal Processing ◽  
Crystallization Behavior ◽  
Sol Gel ◽  
Rapid Thermal Processing ◽  
Lead Zirconate ◽  
Dielectric Constants ◽  
Heating Rates ◽  
Pzt Films

AbstractThe preparation of ferroelectric lead zirconate titanate (PZT) thin films by rapid thermal processing (RTP) is reported. The films were deposited by chemical sol gel and physical sputter techniques. The heating rate of RTP was found to have significant influence on the crystallization behavior. Faster heating rates lead to lowering of the crystallization temperature and reduction of grain size. PZT films were obtained with dielectric constants ~ 1000, remanent polarizations between 20 and 30μC/cm2, coercive fields 20 to 60kV/cm, and no significant fatigue for 109 to 1010 stressing cycles.

Ferroeleciric Thin Films Intended for Electronic Device Applications

1993 ◽  
Vol 310 ◽  
Author(s):  
A. Patel ◽  
E.A. Logan ◽  
R. Nicklin ◽  
N.B. Hasdell ◽  
R.W. Whatmore ◽  
...  
Keyword(s):  
Thin Films ◽  
Flip Chip ◽  
Electronic Device ◽  
Dielectric Material ◽  
Sol Gel ◽  
Deposition Process ◽  
Dielectric Constants ◽  
Excess Lead ◽  
Starting Solutions ◽  
High Dielectric

AbstractThe need for integrated ferroelectrics as charge storage capacitors has increased dramatically not only for use in radiation hardened and commercial non-volatile memories, but also as possible high dielectric material suitable for capacitor applications. These properties combined with a thin film format, offer the capability of forming very compact capacitor structures suitable for MCM applications through Flip-Chip Bonding, or even integrated directly onto MMIC's. In this paper, the material PbZrxTi1-xO3, where x=l, 0.53, and 0.60 has been assessed. Thin films were produced using a sol-gel technique onto metallised thermally oxidised silicon. The effects on film microstructure and crystallinity with variation in the deposition process will be described. The best films were obtained by incorporating excess lead in the starting solutions, and also by the addition of acetylacetone which was used as a solution modifier. It will be demonstrated that fully perovskite films can be readily obtained at temperatures as low as 450°C. The films were normally 0.3-0.44μm thick with grain sizes of the order of 0.2μm. These films exhibited dielectric constants and loss in the range 170-800 and 1-3% respectively. Measurements upto 3MHz, indicated useful performance with low dispersion. The measured Pr and Ec were in the range 16-22μC/cm2, and 60-120kV/cm respectively.

Perovskite crystallization of sol-gel processed (Pb,La0.06,Gd0.02)(Zr0.65,Ti0.35)O3 thin films: Dielectric, ferroelectric and optical properties

2002 ◽  
Vol 17 (10) ◽  
pp. 2652-2659 ◽  
Author(s):  
Reji Thomas ◽  
Shoichi Mochizuki ◽  
Toshiyuki Mihara ◽  
Tadashi Ishida
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Elemental Distribution ◽  
Surface And Interface ◽  
Si Substrates ◽  
Dielectric Constant And Loss ◽  
Direct Band ◽  
Free Films

Ferroelectric lead lanthanum gadolinium zirconium titanate (PLGZT) thin films were prepared by the sol-gel spin coating technique. Three-step preannealing heat treatment was employed to prepare crack-free films. Various types of substrates, and the effects of the seed layer and annealing temperature on the perovskite crystallization were studied. Phase-pure perovskite crystallization was obtained by annealing the films on PbTiO3/Pt/Ti/Si substrates at 700 °C for 30 min. The Auger electron spectroscopy depth profile showed uniform elemental distribution along the thickness except the surface and interface regions. Dielectric constant and loss tangent at 10 kHz were 1000 and 0.06, respectively. Remanent polarization (Pr) and coercive field (Ec) were 11.8 μC/cm2 and 71 kV/cm, respectively. The direct band gap energy was 3.55 eV for the amorphous films. The refractive index and extinction coefficient at 610 nm for amorphous PLGZT films were 2.14 and 0.0028, respectively. The dispersion of the refractive index was interpreted in terms of a single electronic oscillator at 6.06 eV.

Sign in / Sign up

Export Citation Format

Share Document