Improvement in tunability and dielectric loss of (Ba0.5Sr0.5)TiO3 capacitors using seed layers on Pt/Ti/SiO2/Si substrates

2002 ◽  
Vol 17 (11) ◽  
pp. 2831-2836 ◽  
Author(s):  
Young-Ah Jeon ◽  
Woong-Chul Shin ◽  
Tae-Suck Seo ◽  
Soon-Gil Yoon
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Layer Thickness ◽  
Seed Layer ◽  
Root Mean Square Roughness ◽  
Si Substrates ◽  
Low Dielectric ◽  
Bst Films ◽  
Seed Layer Thickness ◽  
Seed Layers

The absence of a low dielectric constant layer at the barium strontium titanate (BST)/Pt interface and a decreased roughness are critical issues in the production of (Ba0.5Sr0.5)TiO3 thin films with high tunabilities and low losses. An improvement in dielectric properties was achieved by the insertion of seed layers at the BST/Pt interface by pulsed laser deposition. The higher tunability can be attributed to (100) texturing of the BST films, which is independent of grain size and grain morphologies, thus leading to a variation in seed layer thicknesses. The tunability and dielectric constant of 1600-Å-thick BST films showed a maximum of 53% and 720, respectively, at a seed layer thickness of 100 Å. Dielectric loss is dependent on the roughness of BST films and reached a minimum of 0.8% at a root mean square roughness of 28 Å. The maximum figures of merit, defined as the ratio of tunability to dielectric loss, of approximately 58 at 100 kHz and 198 kV/cm were obtained at a seed layer thickness of 70 Å. The optimized seed layer thickness for BST deposition onto Pt/Ti/SiO2/Si substrates plays an important role in maintaining the high tunabilities and low loss, which are suitable for microwave device applications.

3C-SiC on Si Substrates Using Pendeo-Epitaxial Growth

2008 ◽  
Vol 600-603 ◽  
pp. 219-222 ◽  
Author(s):  
Byeung C. Kim ◽  
Michael A. Capano
Keyword(s):  
Layer Thickness ◽  
Seed Layer ◽  
Domain Boundary ◽  
Chemical Vapor ◽  
Si Substrates ◽  
Atomic Force ◽  
Process Viability ◽  
Cubic Silicon Carbide ◽  
Sic Films ◽  
Seed Layer Thickness

Cubic silicon carbide (3C-SiC) growth using Pendeo-epitaxy technique was successfully achieved on Si(001) substrates. 3C-SiC was grown by chemical vapor deposition (CVD) with silane and propane as precursors. Effects of underlying stripes and seed 3C-SiC layers thickness on PE 3C-SiC films were investigated. Root mean square (RMS) measurements using atomic force microscope (AFM) showed that surface morphology of PE 3C-SiC films remarkably improves with an increase of the seed 3C-SiC layer thickness, and the values were from 9.8 nm for 3 µm thick seed layer to 0.5 nm for 10 µm thick seed layer thickness. Additionally, domain boundary densities were counted, and the values also strongly depend on the seed layer thickness: from >1500/mm2 for 3 µm seed layer thickness to <100/mm2 for 10 µm seed layer thickness. Pendeo-epiaxial growth profiles with various width/separation dimensions of stripes were also investigated, and stripes with width of 10 µm and separation of 5 µm provide the best profile and process viability.

Skin–core structured fluorinated MWCNTs: a nanofiller towards a broadband dielectric material with a high dielectric constant and low dielectric loss

2018 ◽  
Vol 6 (9) ◽  
pp. 2370-2378 ◽  
Author(s):  
Yang Liu ◽  
Cheng Zhang ◽  
Benyuan Huang ◽  
Xu Wang ◽  
Yulong Li ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Epoxy Composite ◽  
Low Dielectric ◽  
High Dielectric

A novel skin–core structured fluorinated MWCNT nanofiller was prepared to fabricate epoxy composite with broadband high dielectric constant and low dielectric loss.

scholarly journals Crown ether-containing polyimides with high dielectric constant

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23309-23312 ◽  
Author(s):  
Ting Yang ◽  
Wenhui Xu ◽  
Xinwen Peng ◽  
Haoqing Hou
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Crown Ether ◽  
High Dielectric Constant ◽  
Low Dielectric ◽  
High Dielectric

Crown ether-containing polyimides possess high dielectric constant and low dielectric loss, without sacrificing other properties.

Photosensitive Polyimide having low loss tangent for RF application

2018 ◽  
Vol 2018 (1) ◽  
pp. 000476-000482 ◽  
Author(s):  
Masao Tomikawa ◽  
Hitoshi Araki ◽  
Yohei Kiuchi ◽  
Akira Shimada
Keyword(s):  
Molecular Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Frequency ◽  
Low Dielectric Constant ◽  
Low Loss ◽  
Elongation At Break ◽  
Low Dielectric ◽  
The Poor

Abstract Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.

Low-temperature fabrication of high-quality (Ba, Sr)TiO3 films using charged liquid cluster beam method

2002 ◽  
Vol 17 (8) ◽  
pp. 1888-1891 ◽  
Author(s):  
Hyungsoo Choi ◽  
Sungho Park ◽  
Yi Yang ◽  
HoChul Kang ◽  
Kyekyoon (Kevin) Kim ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Low Temperature ◽  
Cluster Beam ◽  
High Quality ◽  
Carboxylate Ligands ◽  
Si Substrates ◽  
Beam Method ◽  
Temperature Deposition ◽  
Bst Films ◽  
Substrate Temperatures

Low-temperature deposition of high-quality (Ba, Sr)TiO3 (BST) thin films was achieved in air on Pt/Ti/SiO2/Si substrates using the charged liquid cluster beam (CLCB) method. The Ba, Sr, and Ti precursors were synthesized using alkoxy carboxylate ligands to tailor their physical properties to the CLCB process. The as-deposited BST films fabricated at substrate temperatures as low as 280 °C exhibited high purity. The leakage current density and dielectric constant of the film, deposited at 300 °C and subsequently annealed at 700 °C, were 2.5 × 10−9 A/cm2 at 1.5 V and 305, respectively.

scholarly journals Colossal dielectric constant of NaNbO3 doped BaTiO3 ceramics

2016 ◽  
Vol 34 (2) ◽  
pp. 322-329 ◽  
Author(s):  
Wan Q. Cao ◽  
Ling F. Xu ◽  
Mukhlis M. Ismail ◽  
Li L. Huang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Traditional Approach ◽  
Temperature Stability ◽  
Bound State ◽  
High Energy ◽  
Low Dielectric ◽  
Giant Dielectric ◽  
Giant Dielectric Constant ◽  
High Dielectric

AbstractBaTiO3 ceramics doped with 0.40 mol% NaNbO3 were prepared using a traditional approach by sintering at temperature of 1250 °C to 1290 °C. The prepared ceramics was characterized by very good dielectric properties, such as high dielectric constant (1.5 × 105), low dielectric loss (0.1), and good dielectric temperature stability in the −40 °C to 100 °C range for the sample sintered below 1270 °C. The dielectric characteristics obtained with XPS confirmed that Ti4+ ions remain in the state without any change. The huge increase in dielectric constant in NaNbO3 doped BaTiO3 samples occurs when large amount of Ba2+ ions are excited to a high energy bound state of Ba2+ − e or Ba+ to create electron hopping conduction. For samples with the content of NaNbO3 higher than 0.40 mol%, or sintering temperature higher than 1280 °C, compensation effect is dominated by cation vacancies with sharply decreasing dielectric constant and increased dielectric loss. The polaron effect is used to explain the relevant mechanism of giant dielectric constant appearing in the ferroelectric phase.

Sign in / Sign up

Export Citation Format

Share Document