ZrO2 Layer Thickness Dependent Electrical and Dielectric Properties of BST/ZrO2/BST Multilayer Thin Films

2011 ◽  
Vol 1368 ◽  
Author(s):  
Santosh K. Sahoo ◽  
D. Misra ◽  
D. C. Agrawal ◽  
Y. N. Mohapatra
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Layer Thickness ◽  
Leakage Current ◽  
Loss Tangent ◽  
Multilayer Structure ◽  
Multilayer Thin Films ◽  
High Dielectric

ABSTRACTRecently, high K materials play an important role in microelectronic devices such as capacitors, memory devices, and microwave devices. Now a days ferroelectric barium strontium titanate [BaxSr1-xTiO3, (BST)] thin film is being actively investigated for applications in dynamic random access memories (DRAM), field effect transistor (FET), and tunable devices because of its properties such as high dielectric constant, low leakage current, low dielectric loss, and high dielectric breakdown strength. Several approaches have been used to optimize the dielectric and electrical properties of BST thin films such as doping, graded compositions, and multilayer structures. We have found that inserting a ZrO2 layer in between two BST layers results in a significant reduction in dielectric constant, loss tangent, and leakage current in the multilayer thin films. Also it is shown that the properties of multilayer structure are found to depend strongly on the sublayer thicknesses. In this work the effect of ZrO2 layer thickness on the dielectric, ferroelectric as well as electrical properties of BST/ZrO2/BST multilayer structure is studied. The multilayer Ba0.8Sr0.2TiO3/ZrO2/Ba0.8Sr0.2TiO3 film is deposited by a sol-gel process on the platinized Si substrate. The thickness of the middle ZrO2 layer is varied while keeping the top and bottom BST layer thickness as fixed. It is observed that the dielectric constant, dielectric loss tangent, and leakage current of the multilayer films reduce with the increase of ZrO2 layer thickness and hence suitable for memory device applications. The ferroelectric properties of the multilayer film also decrease with the ZrO2 layer thickness.

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.

scholarly journals STRUCTURAL AND ELECTRICAL PROPERTIES OF TANTALUM PENTAOXIDE (Ta2O5) THIN FILMS – A REVIEW

2013 ◽  
Vol 22 ◽  
pp. 564-569
Author(s):  
KANTA RATHEE ◽  
B. P. MALIK
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Metal Oxide ◽  
High Dielectric Constant ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Structural And Electrical Properties ◽  
High Dielectric ◽  
Deposited Films

Down scaling of complementary metal oxide semiconductor transistors has put limitations on silicon dioxide to be used as an effective dielectric. It is necessary to replace the SiO 2 with a physically thicker layer of oxides of high dielectric constant. Thus high k dielectrics are used to suppress the existing challenges for CMOS scaling. Many new oxides are being evaluated as gate dielectrics such as Ta2O5 , HfO2 , ZrO2 , La2O3 , HfO2 , TiO2 , Al2O3 , Y2O3 etc but it was soon found that these oxides in many respects have inferior electronic properties to SiO2 . But the the choice alone of suitable metal oxide with high dielectric constant is not sufficient to overcome the scaling challenges. The various deposition techniques and the conditions under which the thin films are deposited plays important role in deciding the structural and electrical properties of the deposited films. This paper discusses in brief the various deposition conditions which are employed to improve the structural and electrical properties of the deposited films.

Low Temperature Deposition of High Dielectric Constant Thin Films for Decoupling Capacitor Applications

1990 ◽  
Vol 203 ◽  
Author(s):  
P. Li ◽  
B. Gittleman ◽  
T.-M. Lu
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
High Dielectric Constant ◽  
Promising Alternative ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Annealing Effects ◽  
Temperature Deposition ◽  
High Dielectric

ABSTRACTHigh dielectric constant thin films for packaging applications were studied. Compared with polycrystalline or epitaxial ferroelectric thin films amorphous ferroelectric films are a promising alternative because of their ease of processing and low leakage current. Reactive Partially Ionized Beam deposition (RPIB) offers a new approach to deposit high dielectric constant films at a low substrate temperature. As an example, the growth of amorphous BaTiOs thin films using RPIB deposition is described. The films were characterized in terms of dielectric constant and leakage current. The annealing effects on the film properties are also discussed.

Effect of La Contents on La-Doped Bi2Ti2O7 Dielectric Thin Films

2013 ◽  
Vol 750-752 ◽  
pp. 931-935
Author(s):  
Xue Na Yang ◽  
Jian An Liu ◽  
Bai Biao Huang ◽  
Si Jiang Gao
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
High Dielectric Constant ◽  
Dielectric Thin Films ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Xrd Patterns ◽  
High Dielectric ◽  
La Doped

La-doped (Bi1-xLax)2Ti2O7 (BLTO) thin films with different La contents have been grown by CSD method. All the XRD patterns of the samples showed that the films were polycrystalline films. The intensities of the peaks decreased with the increasing of La contents. The general trend of the changes of leakage current was decreased with the increasing of x. The case of dielectric constant as a function of La content is complicated. The rule of change of the dielectric constant is different with different la contents. In view of dielectric constant and dielectric loss, we think that the film of x=0.2 has relative low leakage current and high dielectric constant, which is considered to be adequate for a DRAM.

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.

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.

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