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

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.

Download Full-text

Processing and Electrical Properties of Ta and Li-Modified KNN-Based Lead-Free Thin Films Prepared by the RF Sputtering Technology

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.1372 ◽

2012 ◽

Vol 512-515 ◽

pp. 1372-1375 ◽

Cited By ~ 2

Author(s):

Fann Wei Yang ◽

Chien Min Cheng ◽

Kai Huang Chen

Keyword(s):

Thin Film ◽

Thin Films ◽

Leakage Current ◽

Oxygen Concentration ◽

Leakage Current Density ◽

Current Density ◽

Lead Free ◽

Root Mean Square Roughness ◽

Excess Oxygen ◽

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.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-748-u12.8 ◽

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.

Download Full-text

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

Journal of Materials Research ◽

10.1557/jmr.1998.0139 ◽

1998 ◽

Vol 13 (4) ◽

pp. 990-994 ◽

Cited By ~ 19

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.

Download Full-text

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

Journal of Materials Research ◽

10.1557/jmr.1994.2561 ◽

1994 ◽

Vol 9 (10) ◽

pp. 2561-2565 ◽

Cited By ~ 36

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.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-433-33 ◽

1996 ◽

Vol 433 ◽

Cited By ~ 3

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.

Download Full-text

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

MRS Proceedings ◽

10.1557/proc-748-u6.5 ◽

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.

Download Full-text

Effects of Lattice and Thermal Mismatch Induced by Different Seed Layers on (Na0.8K0.2)0.5Bi0.5TiO3 Ferroelectric Thin Film

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.291-294.2636 ◽

2013 ◽

Vol 291-294 ◽

pp. 2636-2640 ◽

Cited By ~ 1

Author(s):

Yue Qiu Gong ◽

Ren Jie Huang ◽

Xu Jun Li ◽

Xue Jun Zheng

Keyword(s):

Thin Film ◽

Thin Films ◽

Leakage Current ◽

Leakage Current Density ◽

Current Density ◽

Perovskite Phase ◽

Ferroelectric Thin Film ◽

Micro Electro Mechanical System ◽

Thermal Mismatch ◽

Seed Layers

(Na0.8K0.2)0.5Bi0.5TiO3 (NKBT20) lead free environmental protection thin films were deposited on Si(100), Pt/Ti/SiO2/Si(100), LaNiO3/SiO2/Si(100) and SrTiO3(STO)/Pt/Ti/SiO2/Si(100) by metal organic decomposition, and the effects of mismatch induced by different seed layers on microstructures, leakage current density, ferroelectric and dielectric properties of these thin films were investigated in detail. The NKBT20/STO thin film with single perovskite phase is of the largest grain size, dielectric constant, remnant polarization and the smallest leakage current density. This could be attributed to the fact that the optimum seed layers can lower the lattice and thermal mismatch between the seed layers and the thin film. The improved electric properties may make NKBT20/STO thin film a promising candidate in micro-electro-mechanical system.

Download Full-text

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.434-435.271 ◽

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.

Download Full-text

Application of Amorphous Zirconium-Yttrium-Aluminum-Magnesium-Oxide Thin Film with a High Relative Dielectric Constant Prepared by Spin-Coating

Membranes ◽

10.3390/membranes11080608 ◽

2021 ◽

Vol 11 (8) ◽

pp. 608

Author(s):

Huiyun Yang ◽

Zhihao Liang ◽

Xiao Fu ◽

Zhuohui Xu ◽

Honglong Ning ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Dielectric Constant ◽

Magnesium Oxide ◽

Leakage Current ◽

Leakage Current Density ◽

Current Density ◽

Relative Dielectric Constant ◽

Oxide Thin Film ◽

Yttrium Aluminum

Amorphous metal oxide has been a popular choice for thin film material in recent years due to its high uniformity. The dielectric layer is one of the core materials of the thin film transistor (TFT), and it affects the ability of charges storage in TFT. There is a conflict between a high relative dielectric constant and a wide band gap, so we solved this problem by using multiple metals to increase the entropy of the system. In this paper, we prepared zirconium-yttrium-aluminum-magnesium-oxide (ZYAMO) dielectric layers with a high relative dielectric constant using the solution method. The basic properties of ZYAMO films were measured by an atomic force microscope (AFM), an ultraviolet-visible spectrophotometer (UV-VIS), etc. It was observed that ZYAMO thin films had a larger optical band when the annealing temperature increased. Then, metal-insulator-metal (MIM) devices were fabricated to measure the electrical properties. We found that the leakage current density of the device is relatively lower and the ZYAMO thin film had a higher relative dielectric constant as the concentration went up. Finally, it reached a high relative dielectric constant of 56.09, while the leakage current density was no higher than 1.63 × 10−6 A/cm2@ 0.5 MV/cm at 1.0 M and 400 °C. Therefore, the amorphous ZYAMO thin films has a great application in the field of high permittivity request devices in the future.

Download Full-text