THICKNESS EFFECTS ON THE EPITAXIAL NATURE OF THE SINGLE-PHASE MULTIFERROIC THIN FILMS

2009 ◽  
Vol 08 (01n02) ◽  
pp. 81-85
Author(s):  
A. HUANG ◽  
S. Y. TAN ◽  
S. R. SHANNIGRAHI
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Film Thickness ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Sol Gel ◽  
Fold Increase ◽  
Xrd Analysis ◽  
Sol Gel Process

Multiferroic Bi 0.95 La 0.05 Fe 0.7 Sc 0.3 O 3 (BLFS) thin films with different thicknesses have been prepared on (1 0 0) LaAlO 3 (LAO) substrates using a sol–gel process and annealed in N 2 ambient at 650°C for 5 min. From the X-ray diffraction (XRD) analysis, it was observed that BLFS thin films had (h 0 0)-preferred orientation for the film thickness 63, 125, 186, and 240 nm and became isotropic thereafter. The films developed in-plane epitaxial growth with respect to the substrate. The surface morphology became denser and the surface roughness increased as thickness increased up to 241 nm. The highest dielectric constant observed for the 241 nm thick BLFS film too. No prominent of the leakage current density observed for the film thickness up to 241 nm. However, two fold increase in the leakage current density observed for the film thickness 382 nm. For the BLFS films with thickness 241 nm, we observed the highest dielectric constant (ε) value of 1675 and remnant polarization (Pr) polarization value of 52 μC/cm2 using a sol–gel spin coating process.

Leakage Current Behavior in CaZrO3 Thin Films for High-k Applications

2004 ◽  
Vol 811 ◽  
Author(s):  
Ting Yu ◽  
Weiguang Zhu ◽  
Xiaofeng Chen ◽  
Yuekang Lu
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Electric Fields ◽  
Current Density ◽  
Breakdown Strength ◽  
Sol Gel ◽  
High K

ABSTRACTElectrical properties and leakage current mechanisms of perovskite CaZrO3 dielectric thin films have been studied in this paper. CaZrO3 thin films were deposited on Pt/SiO2/n-Si substrate by the sol-gel wet chemical technology, and then annealed at temperatures ranging from 550 to 700 °C for 1h in O2. The films with platinum (Pt) top and bottom electrodes were characterized with respect to the leakage current as a function of temperature and applied voltage. The CaZrO3 film annealed at 600 °C was amorphous and showed good electrical properties with a dielectric constant of about 15 and leakage current density of 10−8 A/cm2 at high applied electrical field of 2.5 MV/cm. The data can be interpreted via a Schottky barrier model. The conduction mechanism at low electric fields is due to Ohmic conduction. On the other hand Schottky mechanism dominates at the intermediate fields. The high dielectric constant, low leakage current density and high breakdown strength suggest that the CaZrO3 thin film is a promising candidate for high-k applications.

Effects of Film Thickness on Microstructure and Ferroelectric Properties of Bi3.15Nd0.85Ti3O12 Thin Films Prepared by Sol-Gel Method

2011 ◽  
Vol 239-242 ◽  
pp. 1275-1278
Author(s):  
Chang Yong Liu ◽  
Dong Yun Guo ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Layered Perovskite ◽  
Gel Method ◽  
Sol Gel Method

Bi3.15Nd0.85Ti3O12 (BNT) thin films with different thicknesses (200, 270, 360, 450 and 540 nm) were prepared on Pt/Ti/SiO2/Si substrates by sol–gel method. The effect of film thickness on the microstructure and ferroelectric properties of BNT thin films was investigated. All BNT thin films were consisted of a single phase of bismuth-layered perovskite structure. With increasing film thickness, grains gradually became larger, the remanent polarization (2Pr) firstly increased and then decreased, and the leakage current density showed opposite trend. The 360 nm-thick BNT film exhibited better electrical properties with 2Pr26 µC/cm2, coercive field (2Ec) 220 kV/cm, dielectric constant 345 (at 1 MHz) and low leakage current density.

Preparation and Characterization Of SrTio3 Thin Films Using ECR Plasma Assisted MOCVD

1995 ◽  
Vol 415 ◽  
Author(s):  
Joon Sung Lee ◽  
Han Wook Song ◽  
Dae Sung Yoon ◽  
Byung Hyuk Jun ◽  
Byoung Gon Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Oxygen Plasma ◽  
Grain Structure ◽  
Breakdown Field ◽  
Ecr Plasma ◽  
Step Coverage

ABSTRACTSrTiO3 thin films were prepared on Si(p-type 100) and Pt/SiO2/Si substrates using ECR plasma (or without ECR plasma) assisted MOCVD. Sr(TMI-D)2 and Ti-isopropoxide were used as Sr and Ti metal organic sources, respectively. Perovskite SrTiO3 films were obtained at relatively low temperature of 500°C (using ECR oxygen plasma. Experimental results indicated that higher deposition temperature and ECR oxygen plasma increase the crystallinity, the dielectric constant and the leakage current density. The dielectric constant and the dielectric loss were 222 and 0.04, respectively, for 1234 Å thin SrTiO3 film (Sr/(Sr+Ti)=0.5). The leakage current density was 3.78 × 10−7 A/cm2 at 1.0V, and the dielectric breakdown field was 0.57MV/cm. SEM analyses showed that SrTiO3 films have a uniform and fine grain structure. In terms of step coverage, a lateral step coverage of 50% at 0.8 μm step (the aspect ratio was 1) was obtained with the thickness uniformity of ± 0.5% and the composition uniformity of ±1.2% at 4′′ wafer.

Preparation and Characterization of (Sr1−xTix)O3 and (Ba1−xSrx)TiO3 Thin Films using ECR Plasma Assisted MOCVD

1996 ◽  
Vol 433 ◽  
Author(s):  
Kwangsoo No ◽  
Joon Sung Lee ◽  
Han Wook Song ◽  
Won Jong Lee ◽  
Byoung Gon Yu ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Breakdown Field ◽  
Carrier Gas ◽  
Ecr Plasma

AbstractBa(TMHD)2, Sr(TMHD)2 and Ti-isopropoxide were used to fabricate the (SrxTi1 x)O3 and (Ba1 x Srx)TiO3 thin films. The decomposition and degradation characteristics of Ba(TMHD)2 and Sr(TMHD)2 with storage time were analyzed using a differential scanning calorimeter (DSC). The thin films were fabricated on Si(p-type 100) and Pt/SiO2/Si substrates with Ar carrier gas using ECR plasma (or without ECR plasma) assisted MOCVD. Experimental results showed that the ECR oxygen plasma increased the deposition rate, the ratio of Sr/Ti, the dielectric constant and the leakage current density of the film. The dependency of the crystallinity and the electrical properties on the Sr/Ti ratio of films were investigated. However, almost of the films deposited with Ar carrier gas had slightly high dielectric loss and high leakage current density and showed non-uniform compositional depth profiles. NH3 gas was also used to decrease the degradation of the MO-sources. Mass spectra in-situ monitoring of source vapors in ECR-PAMOCVD system were obtained. By introducing NH3 as a carrier gas, a significant improvement was achieved in the volatility and the thermal stability of the precursors, and the vaporization temperatures of the precursors were reduced compared to Ar carrier gas. The uniform compositional depth profile, less hydrogen and carbon content and the good electrical properties of (SrxTi1−x)O3 thin films were obtained with NH3 carrier gas. The (Ba1−xSrx)TiO3 thin film were fabricated to have very fine and uniform microstructure, the dielectric constant of 456, the dielectric loss of 0.0128, the leakage current density of 5.01 × 10−8A/cm2 at 1V and the breakdown field of 3.65MV/cm.

Effect of Film Thickness on Structure and Property of Pb(Zr0.53Ti0.47)O3 Thin Film

2010 ◽  
Vol 150-151 ◽  
pp. 112-117 ◽  
Author(s):  
Min Xian Shi ◽  
Wei Mao ◽  
Yan Qin ◽  
Zhi Xiong Huang ◽  
Dong Yun Guo
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Film Thickness ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Xrd Analysis ◽  
Structure And Property ◽  
Si Substrates ◽  
Sol Gel Process ◽  
Ferroelectric Hysteresis

Pb(Zr0.53Ti0.47)O3 thin films with thickness of 120nm, 190nm, 310nm, 440nm and 630nm were deposited on Pt/Ti/SiO2/Si substrates by sol-gel process through repeating spining process 2 times, 4 times, 6 times, 8 times and 10 times respectively. The structures of PZT films were investigated by SEM and XRD analysis. The ferroelectric hysteresis loops were recorded by Radiant Precision Workstation and dielectric properties were measured using an Agilent HP4294A impedance analyzer. X-ray diffraction indicated that with the film thickness increasing, the diffraction intensity increased. The thickness of PZT film had great effect on ferroelectric and dielectric properties. Conclusively when the film thickness was about 310nm, the PZT thin films possessed better ferroelectric and dielectric properties.

SrTiO3 Films Prepared by MOCVD Using Novel Sr Source

1994 ◽  
Vol 361 ◽  
Author(s):  
Hideaki Yamauchi ◽  
Takafumi Kimura ◽  
Masao Yamada
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Thick Films ◽  
Relative Dielectric Constant ◽  
Si Substrates ◽  
Vaporization Temperature

ABSTRACTSrTiO3 thin films have been prepared by MOCVD. A novel Sr source of Sr(DPM)2-tetraen2 was used to stabilize source delivery and to reduce the vaporization temperature of Sr source. Films were deposited on Pt/Ta/Si substrates at deposition temperatures from 450 °C to 600 °C. The relative dielectric constant was about 220 at the deposition temperatures from 550 °C to 600 °C for as-deposited 90-nm-thick films. The leakage current density was in the range of 10−7 A/cm2, typically.

Enhancement of the Electrical Properties of BaTiO3 Films on GaAs Using Double Layer Structures

1994 ◽  
Vol 361 ◽  
Author(s):  
L.H. Chang ◽  
W.A. Anderson
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Charge Density ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Double Layer ◽  
Current Density ◽  
Dielectric Constants ◽  
Oxide Charge

ABSTRACTFerroelectric BaTiO3 thin films have been directly deposited on n-GaAs with carrier concentration of 5.3–8.2×1017/cm2. The BaTiO3 thin films with a thickness in the range of 80–120 nm were prepared by RF magnetron sputtering with a substrate temperature of 300°C. The as-deposited BaTiO3 films appeared to be amorphous with relative dielectric constants of around 15 and gave flat capacitance-voltage (C-V) curves, indicating poor interface properties and very high oxide charge density. After rapid thermal annealing (RTA) at 800°C for 60 sec, the relative dielectric constant of the BaTiO3 film increased to 82 and a sharp C-V curve was observed with oxide charge density of about 7×1012/cm2. However, the leakage current density increased from 4×10'11 A/cm2 for as-deposited BaTiO3 to 2×105 A/cm2 for RTA(800°C)-BaTiO3 at a field of 4×105 V/cm. By taking advantage of the best properties from both as-deposited amorphous BaTiO3 films (low leakage current density) and RTA(800°C)-BaTiO3 (high dielectric constant) the double layer structure was designed to enhance the electrical properties of the BaTiO3 films on GaAs. The most promising results in regards to the dielectric property and leakage current density are 76.5 and 9.7×109 A/cm2, respectively, for the double layer RTA(500°C)-BaTiO3 on RTA(800°C)-BaTiO3 structures.

Electrical and Dielectric Characteristics of SrTiO3 Thin Films Grown by PE-MOCVD Technique

1993 ◽  
Vol 335 ◽  
Author(s):  
Z. Q. Shi ◽  
C. Chern ◽  
S. Liang ◽  
Y. Lu ◽  
A. Safari
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Loss ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Room Temperature ◽  
Bottom Electrode ◽  
Electrode Materials ◽  
Mocvd Technique

AbstractEpitaxial strontium titanate (SrTiO3) thin films have been grown by plasma enhanced metalorganic chemical vapor deposition (PE-MOCVD) technique on different bottom electrode materials, such as Pt/MgO and YBCO/LaAlO3. The as grown SrTiO3 film exhibited an epitaxial structure with <100> orientation perpendicular to the substrates as examined by X-ray diffraction (XRD). The electrical and dielectric properties of the films were investigated by capacitance-voltage (C-V) and current-voltage (I-V) measurements in a temperature range from 80K to 300K. The dielectric constant and dielectric loss were found to be 320 and 0.08 at 100 kHz and room temperature. The dc leakage current density and breakdown voltage were strongly dependent on the choice of the bottom electrode materials. For the films grown on YBCO/LaAlO3, the leakage current density is 8.8×10−7 A/cm2 at 200 kV/cm and the breakdown voltage is about 2.0 MV/cm. These results indicated that the SrTiO3 films are suitable for many devices applications. The frequency dependence of the dielectric constant and dielectric loss were studied in the range of 12 Hz to 1 MHz at room temperature. With the increase of the frequency, the dielectric constant showed a little decrease, while the dielectric loss exhibited a sharp increase which could be attributed to the electrode resistance loss.

The Electrical and Physical Properties of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 Thin Films under Conventional Annealing Process

2010 ◽  
Vol 434-435 ◽  
pp. 271-274
Author(s):  
Kai Huang Chen ◽  
Cheng Fu Yang ◽  
Chien Chen Diao
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Physical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
X Ray Diffraction ◽  
Maximum Dielectric Constant ◽  
Xrd Patterns ◽  
Conventional Annealing

In this study, conventional furnace annealing (CFA) is used as the post-treated process, the effects of annealing temperatures on the crystallization and microstructure of (Ba0.7Sr0.3)(Ti0.9 Zr0.1)O3 (BSTZ) thin films will be developed, and the further influences on the electrical properties of BSTZ thin films are also investigated. A previous study made in our laboratory had shown that the dielectric constant and leakage current density of BSTZ thin film with 640 nm thickness are 192 and 10-6 A/cm2 under the frequency of 100 KHz, respectively. However, the maximum dielectric constant and minimum leakage current density of BSTZ thin films under CFA process are 420 (annealed at 800oC) and 10-8 A/cm2 (700oC), respectively. Besides, the X-ray diffraction (XRD) patterns and the SEM morphology show that crystalline features and grain size of BSTZ thin films increase with the increase of CFA-treated temperatures. These experiment results suggest that a strong correlation exhibits that the physical properties will influence the dielectric properties and nucleation features of BSTZ thin films.

Influence of Film Thickness on Dielectric Properties of (Pb0.97La0.02)(Zr0.95Ti0.05)O3 Antiferroelectric Thin Films

2011 ◽  
Vol 194-196 ◽  
pp. 2467-2471
Author(s):  
Jun Liu ◽  
Jing Wang ◽  
Ya Ting Zhang ◽  
Wen Ping Geng ◽  
Xiu Jian Chou
Keyword(s):  
Thin Films ◽  
Electric Field ◽  
Film Thickness ◽  
Current Density ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Phase Switching ◽  
Sol Gel Process ◽  
Maximum Current ◽  
Plzt Thin Films

By the sol-gel process, Pb0.97La0.02(Zr0.95Ti0.05)O3(PLZT) antiferroelectric (AFE) thin films with different thicknesses were successfully deposited on Pt(111)/Ti/SiO2/Si(100) substrates. The phase structure of the PLZT antiferroelectric thin films was studied by X-ray diffraction (XRD) analyses. The electric field-induced AFE-FE phase transformation behavior of the PLZT thin films，was examined by polarization versus field (P-E) and relative permittivity versus field (C-E) measurements, with priority focused on thickness-dependent phase switching field. The current by the polarization and depolarization of polar in the PLZT films was measured through current density-electric field (J-E) measurement. With the increase of film thickness, the maximum polarization less and less, the maximum current density is increasing.

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