LOW LOSS DIELECTRIC MATERIALS FOR HIGH FREQUENCY APPLICATIONS

The microwave properties of some of the low cost materials which can be used in high frequency applications with low transmission losses are investigated in this paper. One of the most accurate microwave characterization techniques, Split Post Dielectric Resonator technique (SPDR) is used for the experimental investigation. The dielectric constants of the 3 materials scrutinized at room temperature and at 10K are 3.65, 2.42, 3.61 and 3.58, 2.48, 3.59 respectively. The corresponding loss tangent values are 0.00370, 0.0015, 0.0042 and 0.0025, 0.0009, 0.0025. The high frequency transmission losses are comparable with many of the conventional materials used in low temperature electronics and hence these materials could be implemented in such applications.

Download Full-text

Effect of current density on the porous silicon preparation as gas sensors**

Journal of the Mechanical Behavior of Materials ◽

10.1515/jmbm-2021-0027 ◽

2021 ◽

Vol 30 (1) ◽

pp. 257-264

Author(s):

Muna H. Kareem ◽

Adi M. Abdul Hussein ◽

Haitham Talib Hussein

Keyword(s):

Porous Silicon ◽

Gas Sensors ◽

Current Density ◽

Room Temperature ◽

Low Cost ◽

High Surface ◽

Volume Ratio ◽

Etching Time ◽

Force Microscopy ◽

Materials Used

Abstract In this study, porous silicon (PSi) was used to manufacture gas sensors for acetone and ethanol. Samples of PSi were successfully prepared by photoelectrochemical etching and applied as an acetone and ethanol gas sensor at room temperature at various current densities J= 12, 24 and 30 mA/cm2 with an etching time of 10 min and hydrofluoric acid concentration of 40%. Well-ordered n-type PSi (100) was carefully studied for its chemical composition, surface structure and bond configuration of the surface via X-ray diffraction, atomic force microscopy, Fourier transform infrared spectroscopy and photoluminescence tests. Results showed that the best sensitivity of PSi was to acetone gas than to ethanol under the same conditions at an etching current density of 30 mA/cm2, reaching about 2.413 at a concentration of 500 parts per million. The PSi layers served as low-cost and high-quality acetone gas sensors. Thus, PSi can be used to replace expensive materials used in gas sensors that function at low temperatures, including room temperature. The material has an exceptionally high surface-to-volume ratio (increasing surface area) and demonstrates ease of fabrication and compatibility with manufacturing processes of silicon microelectronics.

Download Full-text

The Optimization of Extraction of Cordycepin from Fruiting Body of Cordyceps militaris (L.) Link

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.1024 ◽

2011 ◽

Vol 393-395 ◽

pp. 1024-1028 ◽

Cited By ~ 2

Author(s):

Hong Zhang ◽

Jun Wei Wang ◽

Sheng Zhong Dong ◽

Fang Xu Xu ◽

Sheng Hou Wang

Keyword(s):

Fruiting Body ◽

High Performance ◽

Room Temperature ◽

Low Cost ◽

Cordyceps Militaris ◽

Ultrasonic Extraction ◽

Water Extraction ◽

Synergistic Extraction ◽

Control Group ◽

Low Loss

The optimization of extraction of cordycepin from fruiting body of Cordyceps militaris YCC-01 by water extraction, ethanol extraction, ultrasonic extraction, and synergistic extraction is studied in this paper. The optimal conditions, water extraction at 85°C for 2.5h plus ultrasonic extraction at 600W for 35min, were determined through high performance liquid chromatography (HPLC). The dried fruiting body of cordycepin content was 9.559 mg/g by this synergistic extraction method. The yield was 66.2% higher than the control group 85°C water extraction 2.5h and 11.3% higher than the room temperature ultrasonic extraction 35min. This method has a short extraction time, low cost, low loss of active ingredients and other characteristics with good prospects.

Download Full-text

Development of Laser and Photodefinable Toughened Benzocyclobutene Dielectric Materials for 3D-TSV Integration

International Symposium on Microelectronics ◽

10.4071/isom-2013-ta31 ◽

2013 ◽

Vol 2013 (1) ◽

pp. 000067-000071

Author(s):

Zidong Wang ◽

Michael Gallagher ◽

Kevin Wang ◽

Elissei Iagodkine ◽

Mark Oliver ◽

...

Keyword(s):

Fracture Toughness ◽

Moisture Absorption ◽

Dielectric Materials ◽

Copper Interconnects ◽

Size Factor ◽

Low Loss ◽

Low Dielectric ◽

Materials Used ◽

Signal Routing ◽

Stress Buffer

3D IC integration based on TSV technology has been recognized as a key enabler for next generation of electronic devices with reduced size factor and improved performances. The adoption of 3D-TSV technology also requires the development of innovative interconnect solutions that reduces the size of signal routing and therefore imposes new demands on dielectric materials used to isolate the copper interconnects. Benzocyclobutene polymers (Dow's CYCLOTENE™ Advanced Electronic Resins) have been used to isolate copper interconnects in packaging applications for more than 20 years, due to a number of good attributes of the BCB polymer including low copper drift rate, low dielectric constant and low loss, low moisture absorption and proven reliability. However, the low fracture toughness and low elongation of BCB polymer has limited its use in stress buffer applications due to solder bump failure. Here we report the development of new laser and photodefinable toughened benzocyclobutene (BCB) dielectric materials that have following improved properties and benefits over commercial materials including: 1) Higher elongation to break at 25%, 2) Higher fracture toughness, 3) Improved lithographic performance, < 8μm minimal size feature, 4) Better stability, no change in Eo after 30 days at room temperature. The patterning and integration of these toughened benzocyclobutene materials and the processing conditions are also discussed. We believe this toughened BCB material will find wide applications as a stress buffer layer in 3-D IC.

Download Full-text

A colossal dielectric constant of an amorphous TiO2:(Nb, In) film with low loss fabrication at room temperature

Journal of Materials Chemistry C ◽

10.1039/c4tc00500g ◽

2014 ◽

Vol 2 (33) ◽

pp. 6790-6795 ◽

Cited By ~ 70

Author(s):

Zhigang Gai ◽

Zhenxiang Cheng ◽

Xiaolin Wang ◽

Lanling Zhao ◽

Na Yin ◽

...

Keyword(s):

Dielectric Constant ◽

Solid State ◽

High Performance ◽

Room Temperature ◽

Dielectric Materials ◽

Low Loss ◽

Amorphous Tio2 ◽

Colossal Dielectric Constant

High-performance dielectric materials continue to arouse considerable interest due to their application in the field of solid state capacitors.

Download Full-text

High Temperature Capacitors Based on [0001] and [1120] Sapphire Dielectrics

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/hitec-lchen-wa12 ◽

2010 ◽

Vol 2010 (HITEC) ◽

pp. 000182-000187

Author(s):

Liang-Yu Chen

Keyword(s):

High Temperature ◽

Room Temperature ◽

Dielectric Material ◽

Dielectric Materials ◽

Dielectric Constants ◽

Polycrystalline Alumina ◽

Temperature Range ◽

Sapphire Substrates ◽

Low Volume ◽

Parallel Resistance

The test results of the dielectric properties of [0001] (C-plane) and [1120] (A-plane) sapphire (single crystalline Al2O3) at high temperatures indicate that these materials have very stable dielectric constants and low dielectric losses (compared with polycrystalline alumina) at low frequencies in the temperature range from room temperature to 550°C. Therefore, sapphire materials have become likely candidate dielectric materials for high temperature capacitors. This paper reports prototype low-volume (∼100pF) capacitors based on sapphire dielectrics for high temperature and low frequency applications. Low-volume parallel-plate capacitors using C-plane and A-plane sapphire as dielectric material were fabricated by stacking metallized sapphire substrates. These prototype capacitors were characterized in the temperature range from room temperature to 550°C by measuring the capacitance and parallel resistance of these devices at 120Hz, 1kHz, 10kHz, 100kHz, and 1MHz. The capacitance and equivalent parallel resistance of these capacitors were all directly measured by an AC LCZ impedance meter in controlled temperature environments. These prototype devices demonstrate stable capacitances over a wide temperature range, and therefore, have the potential to be integrated with silicon carbide (SiC) devices to enable high temperature electronics. The needs of thin-film metallization and encapsulation for these sapphire substrates are also discussed.

Download Full-text

Low-cost planar coupled-line sensor for permittivity measurement of low-loss dielectric materials in a wide frequency range

2017 Conference on Microwave Techniques (COMITE) ◽

10.1109/comite.2017.7932363 ◽

2017 ◽

Author(s):

Ilona Piekarz ◽

Konrad Janisz ◽

Jakub Sorocki ◽

Krzysztof Wincza ◽

Slawomir Gruszczynski

Keyword(s):

Low Cost ◽

Dielectric Materials ◽

Wide Frequency Range ◽

Frequency Range ◽

Low Loss ◽

Coupled Line ◽

Permittivity Measurement

Download Full-text

The Effect of Different Dielectric Materials in Designing High-Performance Metal-Insulator-Metal (MIM) Capacitors

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v7i3.pp1554-1561 ◽

2017 ◽

Vol 7 (3) ◽

pp. 1554

Author(s):

M. A. Zulkifeli ◽

S. N. Sabki ◽

S. Taking ◽

N. A. Azmi ◽

S. S. Jamuar

Keyword(s):

Breakdown Voltage ◽

High Performance ◽

Dielectric Materials ◽

Dielectric Constants ◽

Metal Insulator ◽

Low Leakage ◽

Dielectric Layers ◽

Metal Insulator Metal ◽

Materials Used ◽

Mim Capacitors

A Metal-Insulator-Metal (MIM) capacitor with high capacitance, high breakdown voltage, and low leakage current is aspired so that the device can be applied in many electronic applications. The most significant factors that affect the MIM capacitor’s performance is the design and the dielectric materials used. In this study, MIM capacitors are simulated using different dielectric materials and different number of dielectric layers from two layers up to seven layers. The effect of the different dielectric constants (k) to the performance of the MIM capacitors is also studied, whereas this work investigates the effect of using low-k and high-k dielectric materials. The dielectric materials used in this study with high-k are Al2O3 and HfO2, while the low-k dielectric materials are SiO2 and Si3N4. The results demonstrate that the dielectric materials with high-k produce the highest capacitance. Results also show that metal-Al2O3 interfaces increase the performance of the MIM capacitors. By increasing the number of dielectric layers to seven stacks, the capacitance and breakdown voltage reach its highest value at 0.39 nF and 240 V, respectively.

Download Full-text

Numerical Investigation of Rayleigh, Sezawa and Love Modes in C-Axis Tilted ZNO/SI for Gas and Liquid Multimode Sensor

Journal of Mechanics ◽

10.1017/jmech.2019.14 ◽

2019 ◽

Vol 36 (1) ◽

pp. 7-18

Author(s):

F. Laidoudi ◽

F. Boubenider ◽

C. Caliendo ◽

M. Hamidullah

Keyword(s):

Atmospheric Pressure ◽

High Frequency ◽

Room Temperature ◽

Electromechanical Coupling ◽

Element Analysis ◽

Gas Concentration ◽

Phase Velocity Dispersion ◽

Micro Sensor ◽

Materials Used ◽

Piezoelectric Thin Film

ABSTRACTFinite element analysis is carried out to investigate the characteristics of Rayleigh, Sezawa and Love surface acoustic modes travelling along c-axis tilted ZnO layer on Si (001) half-space. The phase velocity dispersion curves, electromechanical coupling, reflectivity and mass loading sensitivity are studied for different electroacoustic coupling configurations and c-axis tilt angles θ. The behavior of Rayleigh and Sezawa modes operating as gas sensor, was simulated under the hypothesis that the ZnO free surface is covered with a thin polyisobutylene (PIB) film, 0.2 μm thick, able to selectively adsorb volatile gases at atmospheric pressure and room temperature. The sensor sensitivity to gas concentration in air, i.e. the frequency shifts per unit gas concentration, is studied and compared to some common materials used in literature. The obtained results, demonstrate the feasibility of high-frequency multimode micro-sensor based on the c-axis tilted ZnO piezoelectric thin film and operating in both liquid and gaseous environments.

Download Full-text

PREPARATION OF BUFFER LAYERS ON SAPPHIRE FOR HIGH Tc SUPERCONDUCTING THIN FILMS

Modern Physics Letters B ◽

10.1142/s0217984991001544 ◽

1991 ◽

Vol 05 (19) ◽

pp. 1267-1273 ◽

Cited By ~ 3

Author(s):

X. D. WU ◽

R. E. MUENCHAUSEN

Keyword(s):

Thin Films ◽

High Frequency ◽

Dielectric Constants ◽

Buffer Layers ◽

Processing Temperature ◽

Superconducting Thin Films ◽

Superconducting Properties ◽

Stabilized Zirconia ◽

Low Loss ◽

High Tc

Sapphire is a preferred substrate for high frequency applications where small dielectric constants and low loss tangents are required. It is also much cheaper than other oxide subsrates such as SrTiO 3, LaAlO 3, NdGaO 3, MgO, and yttria-stabilized zirconia (YSZ) for high T c superconducting thin films. Unfortunately, sapphire is not chemically compatible with the high T c superconductors at the processing temperature required to obtained good superconducting properties. As a result, an appropriate buffer layer on sapphire is required.

Download Full-text