Leakage current of Al- or Nb-doped Ba0.5Sr0.5TiO3 thin films by rf magnetron sputtering

1998 ◽  
Vol 13 (4) ◽  
pp. 990-994 ◽  
Author(s):  
Tae-Gyoung In ◽  
Sunggi Baik ◽  
Sangsub Kim
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Elevated Temperatures ◽  
Rf Magnetron Sputtering ◽  
Bst Thin Films ◽  
Bst Thin Film

The effects of Al and Nb doping on the leakage current behaviors were studied for the Ba0.5Sr0.5TiO3 (BST) thin films deposited on Pt/Ti/SiO2/Si(100) substrate by rf magnetron sputtering. Al and Nb were selected as acceptor and donor dopants, respectively, because they have been known to replace Ti-sites of the BST perovskite. The BST thin films prepared in situ at elevated temperatures showed relatively high leakage current density and low breakdown voltage. However, the BST thin films deposited at room temperature and annealed subsequently in air showed improved electrical properties. In particular, the leakage current density of the Al-doped BST thin film was measured to be around 10−8 A/cm2 at 125 kV/cm, which is much lower than those of the undoped or Nb-doped thin films. The results suggest that the Schottky barriers at grain boundaries in the film interior could determine the leakage behavior in the BST thin films.

Preparation of Bi2SiO5-SrBi2Ta2O9 Ferroelectric Thin Films by RF Magnetron Sputtering

2002 ◽  
Vol 748 ◽  
Author(s):  
Shin Kikuchi ◽  
Hiroshi Ishiwara
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Remnant Polarization ◽  
Rf Magnetron Sputtering ◽  
Ferroelectric Thin Films ◽  
Ferroelectric Films ◽  
Typical Composition

ABSTRACTSi-added SrBi2Ta2O9 (SBT) ferroelectric films were prepared by RF magnetron sputtering on a Pt/Ti/SiO2/Si (100) structure. The films were deposited at temperatures below 100°C for preventing Bi evaporation and crystallized at 800°C in air. A typical composition was Sr0.79Bi2.37Ta2.00Si0.2Ox. The remnant polarization value(2Pr) of the Si-added SBT film was 16C/cm2 and leakage current density was 5×10-8A/cm2. The current density was significantly decreased by adding Si atoms.

Orientation Control and Dielectric Properties of Ba0.6Sr0.4TiO3 Thin Films on Pt/Ti/SiO2/Si Substrates with PbO Seeding Layer

2013 ◽  
Vol 741 ◽  
pp. 11-17
Author(s):  
Xiao Hua Sun ◽  
Ya Xia Qiao ◽  
Shuang Hou ◽  
Ying Yang ◽  
Cai Hua Huang
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Precursor Solution ◽  
Seeding Layer ◽  
Bst Thin Films ◽  
Si Substrates ◽  
Bst Thin Film

Ba0.6Sr0.4TiO3 (BST) thin films were fabricated by solgel technique on Pt/Ti/SiO2/Si substrate without and with PbO seeding layer from precursor solutions with different concentrations. The crystal structure, surface morphology, dielectric properties and leakage current density of BST thin films are investigated as functions of the concentration of PbO precursor solution. Its found that the growth orientation of BST thin films with PbO seeding layer can be modulated through adjusting the concentration of PbO precursor solution. BST thin film with PbO seeding layer from 0.05 M precursor solution shows the highest dielectric constant and tunability, which may be attributed to the high crystallization and amplitude of the polarization in high (100) preferred orientated films. The leakage current density of BST films increases with the increasing concentration of PbO precursor solution and agrees well with the space-charge-limited current mechanism at room temperature.

Electrical and Physical Properties of Sodium Potassium Niobates Thin Films Prepared by rf Magnetron Sputtering Technology

2011 ◽  
Vol 239-242 ◽  
pp. 532-535
Author(s):  
Chien Min Cheng ◽  
Shih Fang Chen ◽  
Jen Hwan Tsai ◽  
Kai Huang Chen ◽  
Hsiu Hsien Su
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Physical Properties ◽  
Leakage Current ◽  
Oxygen Concentration ◽  
Leakage Current Density ◽  
Current Density ◽  
Rf Magnetron Sputtering ◽  
Average Grain Size

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.

Characterization of Mis Capacitor of Bst Thin Films Deposited on Si by Rf Magnetron Sputtering

1996 ◽  
Vol 433 ◽  
Author(s):  
S.H. Paek ◽  
C.S. Park ◽  
J.H. Won ◽  
K.S. Lee
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Leakage Current ◽  
Oxygen Concentration ◽  
Rf Magnetron Sputtering ◽  
Si Substrate ◽  
Bst Thin Films ◽  
Mis Capacitor ◽  
High Dielectric ◽  
Mis Capacitors

AbstractThe application of high dielectric (Ba, Sr)TiO3 [BST] thin films for Metal-Insulator- Semiconductor(MIS) capacitors was investigated. BST thin films were deposited on p-Si(100) substrates by the RF magnetron sputtering with temperature range of 500–600 °C. We examined the characteristics of MIS capacitor with various oxygen pressure, substrate temperature and (Ba+Sr)/Ti ratio. The dielectric properties of MIS capacitors consisting of AI/BST/SiO2/Si sandwich structure were measured for various conditions. The charge state densities of the MIS capacitors were determined by high frequency (1 MHz) C-V measurement. Also, current-voltage characteristics of the MIS capacitor were investigated. In order to reduce the leakage current in MIS capacitor, high quality SiO2 layer was grown on bare p-Si substrate by thermal oxidation. By applying SiO2 layer between BST thin films and Si substrate, low leakage current of 10−10 order was observed. Futhermore, the leakage current showed the dependence on the oxygen concentration in plasma gas and the (Ba+Sr)/Ti ratio. Also, the BST MIS structure showed relatively high capacitance even though it is the combination of high-dielectric BST thin films and SiO2 layer. By C-V measurement, the polarity of effective oxide charge changed with the oxygen concentration in plasma gas and (Ba+Sr)/Ti ratio of sputtering target.

Influence of Ta2O5, TiO2, and ZrO2 Interfacial Layers on Structural and Electrical Properties of Laser Ablated Ba0.5Sr0.5TiO3 Thin Films

2002 ◽  
Vol 748 ◽  
Author(s):  
Suprem R. Das ◽  
Rasmi R. Das ◽  
P. Bhattacharya ◽  
Ram S. Katiyar
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Buffer Layers ◽  
Bst Thin Films ◽  
Interfacial Layers ◽  
Average Grain Size ◽  
Structural And Electrical Properties

ABSTRACTPulsed laser deposition technique was used to fabricate Ba0.5Sr0.5TiO 3 (BST) thin-films on Pt/TiO 2/SiO2/Si substrates. The influence of thin interfacial layers of Ta2O5, TiO2, and ZrO2, on the structural and electrical properties of BST thin films was investigated. Insertion of interfacial layers does not affect the perovskite phase formation of BST thin films. Buffer layers helped to make uniform distribution of grains and resulted in a relative increase in the average grain size. The dielectric tunability of BST thin films was reduced with the presence of buffer layers. A BST thin film having a dielectric permitivity of 470 reduced to 337, 235 and 233 in the presence of Ta2O5, TiO2, and ZrO2 layers, respectively. The reduction of the relative dielectric permittivity of BST films with the insertion of interfacial layers was explained in terms of a series capacitance effect, due to the low dielectric constant of interfacial layers. The TiO2 layer did not show any appreciable change in the leakage current density. Deposition of thin Ta2O5 and ZrO2 interfacial layer on top of Pt reduced the leakage current density by an order of magnitude.

The Influence of Oxygen Plasma Treatment on the Electrical Properties of (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 267-270
Author(s):  
Kai Huang Chen ◽  
Cheng Fu Yang
Keyword(s):  
Thin Films ◽  
Plasma Treatment ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Oxygen Plasma ◽  
Rf Magnetron Sputtering ◽  
Dielectric Constants ◽  
Oxygen Plasma Treatment ◽  
Electrical Characteristics

The (Ba0.7Sr0.3)(Ti0.9Zr0.1)O3 (BSTZ) thin films are deposited using radio frequency (RF) magnetron sputtering, then oxygen gas plasma is treated on the surface of BSTZ thin films. The influence of oxygen plasma on the structure of BSTZ thin films is studied using X-ray diffraction patterns and the influence on the electrical characteristics is developed using an Al/BSTZ/Pt/Ti/SiO2/Si capacitor structure. As compared to that of the BSTZ thin films are not subjected to oxygen plasma treatment, experimental results reveal that the leakage current density of the BSTZ thin films in oxygen plasma treatment decreases as much as two orders in magnitude. In addition, the dielectric constants apparently increase and the leakage current density critically decrease as the oxygen-plasma-treated time increases. These results clearly indicate that the electrical characteristics of the BSTZ films are effectively improved using the process of oxygen plasma surface treatment.

A Study on the Improvement of Characteristics of BST Thin Films Fabricated on Iridium Electrode

1997 ◽  
Vol 493 ◽  
Author(s):  
Deok-Sin Kil ◽  
Byung-Il Lee ◽  
Seung-Ki Joo
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Bottom Layer ◽  
Equivalent Thickness ◽  
Bst Thin Films ◽  
Low Leakage ◽  
Low Leakage Current

ABSTRACTBST thin films have been fabricated by RF magnetron sputtering onto Ir layer as a bottom electrode. When the substrate temperature was maintained at 600 °C during deposition, BST films deposited at that temperature showed very small oxide equivalent thickness of 0.36nm as well as very low leakage current density of about 10−8A/cm2at 1.5V. But as substrate temperature was increased to 700 °C in order to obtain high dielectric constant, oxide equivalent thickness exhibited very low value of about 0.3nm, however, leakage current density drastically increased to 10−4/cm2. BST thin films were fabricated by two step process, which consists of bottom layer deposited at high substrate temperature of 700 °C and top layer deposited at low substrate temperature. In the case of BST thin films which are composed of 20nm thick bottom layer deposited at 700 °C and 30nm thick top layer deposited at 500 °C, we obtained very small oxide equivalent thickness of 0.31nm and low leakage current density of 4 × 10−8A/cm2. at 1.5V.

Surface and interface properties of ferroelectric BaTiO3 thin films on Si using RuO2 as an electrode

1994 ◽  
Vol 9 (10) ◽  
pp. 2561-2565 ◽  
Author(s):  
Q.X. Jia ◽  
L.H. Chang ◽  
W.A. Anderson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Dielectric Constant ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Bottom Electrode ◽  
Rf Magnetron Sputtering ◽  
Interface Properties ◽  
Surface And Interface

Ferroelectric BaTiO3 thin films were deposited on Si by rf magnetron sputtering. A conductive oxide, RuO2, was used as the bottom electrode of the capacitors. The performance of the thin film capacitors was found to be a strong function of the surface and interface properties between ferroelectric BaTiO3 and the bottom electrode. A suitable capacitor configuration must be used to preserve the bottom electrode, to enhance the dielectric constant, and to reduce the leakage current density of the films. BaTiO3 thin film on the RuO2/Si substrate, where the BaTiO3 thin film has a bilayer structure of polycrystalline on microcrystalline, showed a dielectric constant of 125 at a frequency of 1 MHz, leakage current density of 10−6 A/cm2 at a field intensity of 2.5 × 105 V/cm, and a breakdown voltage above 106 V/cm.

Comparison Between In-situ Annealing and External Annealing For Barium Ferrite Thin Films Made by RF Magnetron Sputtering

2005 ◽  
Vol 875 ◽  
Author(s):  
A. R. Abuzir ◽  
W. J. Yeh
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Saturation Magnetization ◽  
Barium Ferrite ◽  
Rf Magnetron Sputtering ◽  
Silicon Substrates ◽  
Axis Orientation ◽  
Average Value ◽  
Ferrite Thin Films

AbstractDue to their large magnetic anisotropy perpendicular to the film plane, barium ferrite thick films (BaFe12O19, or BaM) with c-axis orientation are attractive candidates for microwave applications [1,2]. Barium ferrite thin films on silicon substrates without under layer have been deposited under various conditions by RF magnetron sputtering. The structure of the as-grown films is amorphous. External annealing in air has been done at 950°C for ten minutes to crystallize the films. C-axis oriented thin films with squareness of about 0.87 and coercivity of about 3.8KOe are obtained.Thick BaM films with c-axis orientation are difficult to achieve with one single deposition. Multilayer technique looks promising to grow thick films [3]. The external annealing process is difficult to incorporate with the multilayer procedure. An in-situ annealing procedure has been developed to obtain films, which can be used as the basic component for future multilayer deposition. Barium ferrites are first magnetron sputtered on bare silicon substrates in Ar + O2 atmosphere at substrate temperature of 500-600°C, the deposition pressure was kept about 0.008 torr. After the deposition, the temperature of the substrate is immediately increased to about 860°C for ten minutes in 140 torr of argon (80%) and oxygen (20%) mixture of gas, which was introduced into the chamber without breaking the vacuum. With the in-situ process, c-axis oriented thin films of 0.88 squareness and coercivity value of about 4.3KOe are obtained.Both annealing methods seem to have the similar effect on the perpendicular squareness and coercivity at various film thicknesses. The average value of the saturation magnetization Ms obtained from the in-situ annealing using multilayer technique is higher than that of the external one. We have grown films up to 1.0 micron thickness using the multilayer technique, in which three layers of 0.3 μm thickness each are deposited until the final thickness is reached. After the deposition of each layer, it was in-situ annealed before starting the deposition of the next layer. With the multilayer technique, coercivity of about 3.5 KOe and average value of the saturation magnetization Ms of about 4.0 K Gauss is obtained.

Growth of Epitaxial Site-Engineered Bi4Ti3O12-Basded Thin Films by Mocvdand Their Characterization

2002 ◽  
Vol 748 ◽  
Author(s):  
Hiroshi Funakubo ◽  
Tomohiro Sakai ◽  
Takayuki Watanabe ◽  
Minoru Osada ◽  
Masato Kakihana ◽  
...  
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Leakage Current Density ◽  
Current Density ◽  
Spontaneous Polarization ◽  
Chemical Vapor ◽  
The Other ◽  
Other Hand ◽  
La Substitution ◽  
Lower Temperature

ABSTRACTThin films of BIT, La-substituted BIT (BLT) and La- and V-cosubstituted BIT(BLTV) were epitaxially grown on SrRuO3//SrTiO3 substrates at 850°C by metalorganic chemical vapor deposition (MOCVD), and their electrical properties were systematically compared. All films on (100), (110) and (111)-oriented substrates were epitaxially grown with (001)-, (104)-/(014)-and (118) –preferred orientations, respectively. The leakage current density of the BLTV film was almost the same with that of the BLT film, but was smaller than that of BIT film, suggesting that the La substitution contributed to the decrease of the leakage current density especially in pseudoperovskite layer. Spontaneous polarization of the BLTV film was estimated to be almost the same with the BLT film but was smaller that that of the BIT film. This is explained by the decrease of Tc with the La substitution, while V did not contribute to the change of the Curie temperature (Tc ). On the other hand, the coercive field (Ec) value of the BLTV was smaller than that of the BIT and the BLT films. As a result, La substitution contributed to the decrease of the leakage current density together with the decrease of the spontaneous polarization due to the decrease of the Tc. On the other hand, V substitution contributes to the decrease of the defects that suppress the domain motion and increases the Ec value. Therefore, each substitution of La and V plays different roles and this contribution is remarkable for the films deposited at lower temperature.

Sign in / Sign up

Export Citation Format

Share Document