scholarly journals The variation of propagation velocity according to substrate material of band pass filter

2018 ◽  
Vol 7 (3.3) ◽  
pp. 393
Author(s):  
Dong Yoon Lee
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Shape ◽  
Preferential Orientation ◽  
Zno Thin Films ◽  
Band Pass Filter ◽  
Zno Thin Film ◽  
Pass Filter ◽  
Band Pass ◽  
Lift Off

Background/Objectives: The SAW filter has a frequency characteristic determined by the geometry of the IDT electrode, and is widely used as a band-pass filter for passing only a signal having a specific frequency.Methods/Statistical analysis: The features of this filter are high stability and reliability and enable mass production using semiconductor processes.Findings: The MCB process lift off method was used to fabricate the filter to solve the difficulties of the SAW filter process. In particular, we fabricated ZnO thin films with excellent c-axis preferential orientation, high resistivity of more than 106Ωcm, and flat surfaces, and fabricated SAW filters using ZnO thin films as deposition conditions suitable for application to SAW filters. ZnO thin films deposited under conditions of RF power of 150W, chamber pressure of 10mTorr, substrate temperature of 200 ° C and gas mixture ratio of Ar/O2 of 50/50 as sputtering gas have excellent c-axis preferential orientation, high specific resistance and flat surface shape. Then, ZnO piezoelectric thin film was deposited on SiO2 substrate by RF magnetron sputtering method and the SAW filter was fabricated by the MCB lift off method to analyze the frequency characteristics. In addition, compared with the SAW filter fabricated on the LiNbO3 substrate, which is a piezoelectric substrate.Improvements/Applications: The propagation speed of the SAW filter using the ZnO thin film was determined by the variation of the center frequency due to the deposition of the ZnO thin film. 

scholarly journals Effects of Thermal Annealing on the Characteristics of High Frequency FBAR Devices

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Annealing ◽  
Electromechanical Coupling ◽  
Zno Thin Films ◽  
Electromechanical Coupling Coefficient ◽  
Back Side ◽  
Zno Thin Film ◽  
Frequency Responses ◽  
Sputtering System

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.

Plasma Pre-Treatment of Polyethylene Terephthalate Substrate Influence on the Properties of ZnO Thin Film

2014 ◽  
Vol 895 ◽  
pp. 41-44
Author(s):  
Seiw Yen Tho ◽  
Kamarulazizi Ibrahim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Water Contact ◽  
Pre Treatment ◽  
Pet Substrate

In this work, the influences of plasma pre-treatment on polyethylene terephthalate (PET) substrate to the properties of ZnO thin film have been carried out. ZnO thin films were successfully grown on PET substrate by spin coating method. In order to study the effects of plasma pre-treatment, a comparison of treated and untreated condition was employed. Water contact angle measurement had been carried out for PET wettability study prior to ZnO thin film coating. Morphology study of ZnO thin film was performed by scanning probe microscope (SPM). Besides, optical study of the ZnO thin film was done by using UV-vis spectrophotometer. All the measured results show that plasma pre-treatment of PET substrate plays an important role in enhancing the wettability of PET and optical properties of the ZnO thin films. In conclusion, pre-treatment of PET surface is essential to produce higher quality ZnO thin film on this particular substrate in which would pave the way for the integration of future devices.

Enhanced UV Photon-response of Tin Nano Cluster Loaded- laser Irradiated ZnO Thin film detector

2011 ◽  
Vol 1288 ◽  
Author(s):  
Rashmi Menon ◽  
K. Sreenivas ◽  
Vinay Gupta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Surface States ◽  
Response Speed ◽  
Rf Magnetron Sputtering ◽  
Fast Response ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Photo Response

ABSTRACTZinc Oxide (ZnO), II-VI compound semiconductor, is a promising material for ultraviolet (UV) photon sensor applications due to its attractive properties such as good photoconductivity, ease processing at low temperatures and excellent radiation hardness. The rf magnetron sputtering is a suitable deposition technique due to better control over stoichiometry and deposition of uniform film. Studies have shown that the presence of surface defects in ZnO and subsequently their passivation are crucial for enhanced photo-response characteristics, and to obtain the fast response speed. Worldwide efforts are continuing to develop good quality ZnO thin films with novel design structures for realization of an efficient UV photon sensor. In the present work, UV photon sensor is fabricated using a ZnO thin films deposited by rf magnetron sputtering on the corning glass substrate. Photo-response, (Ion/Ioff) of as-grown ZnO film of thickness 100 nm is found to be 3×103 with response time of 90 ms for UV intensity of 140 μW/cm2 (λ = 365 nm). With irradiation on ZnO thin film by pulsed Nd:YAG laser (forth harmonics 266 nm), the sensitivity of the UV sensor is found to enhance. The photo-response increases after laser irradiation to 4x104 with a fast response speed of 35 ms and attributed to the change in surface states and the native defects in the ZnO thin film. Further, enhancement in the ultraviolet (UV) photo-response (8×104) of detector was observed after integrating the nano-scale islands of Sn metal on the surface of laser irradiated ZnO thin film.

ELECTRICAL AND OPTICAL PROPERTIES OF ZnO THIN FILMS PREPARED BY R.F. MAGNETRON SPUTTERING

2011 ◽  
Vol 25 (20) ◽  
pp. 2741-2749 ◽  
Author(s):  
J. C. ZHOU ◽  
L. LI ◽  
L. Y. RONG ◽  
B. X. ZHAO ◽  
Y. M. CHEN ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Oxide Thin Film ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Electrical And Optical Properties ◽  
Axis Orientation ◽  
Sputtering Power

High transparency and conductivity of transparent conducting oxide thin film are very important for improving the efficiency of solar cells. ZnO thin film is a better candidate for transparent conductive layer of solar cell. N-type ZnO thin films were prepared by radio-frequency magnetron sputtering on glass substrates. ZnO thin films underwent annealing treatment after deposition. The influence of the sputtering power on the surface morphology, the electrical and optical properties were studied by AFM, XRD, UV2450 and HMS-3000. The experimental results indicate that the crystal quality of ZnO thin film is improved and all films show higher c-axis orientation with increasing sputtering power from 50 to 125 W. The average transparency of ZnO thin films is higher than 90% in the range of 400–900 nm between the sputtering power of 50–100 W. After the rapid thermal annealing at 550°C for 300 s under N2 ambient, the minimum resistivity reach to 10-2Ω⋅ cm .

TUNABLE BAND-PASS FILTER USING INTERDIGITAL CAPACITOR BY BARIUM STRONTIUM TITANATE (BST) THIN FILMS

2006 ◽  
Vol 86 (1) ◽  
pp. 141-148 ◽  
Author(s):  
TAE-SOON YUN ◽  
HEE NAM ◽  
KI-CHUL YOON ◽  
JONG-CHUL LEE ◽  
HYUN-SUK KIM ◽  
...  
Keyword(s):  
Thin Films ◽  
Strontium Titanate ◽  
Barium Strontium Titanate ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Bst Thin Films ◽  
Interdigital Capacitor ◽  
Barium Strontium ◽  
Band Pass

scholarly journals Some Useful Design Parameters of Non-Uniform Integrated Band-Pass Filters

1983 ◽  
Vol 11 (1) ◽  
pp. 65-70
Author(s):  
H. R. Singh
Keyword(s):  
Thin Film ◽  
Performance Characteristics ◽  
Design Parameters ◽  
Distributed Parameter ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Pass ◽  
Relationship Of ◽  
Important Design ◽  
Terminal Band

Important design parameters for a two-port three-terminal band-pass filter configuration of the integrated thin-film exponential distributed parameter R–C–KR microstructure are presented. The circuit exhibits load independent characteristics. The changes in the value of design parameters under varying loading conditions are given. Various plots illustrating the inter-relationship of the different parameters with each other that can serve as guidelines for a system designer to obtain a pre-assigned pattern of the performance characteristics of the microstructure are included.

A SAW Filter of Elliptic Structure IDT

2014 ◽  
Vol 665 ◽  
pp. 623-628
Author(s):  
Dai Qiang Wang ◽  
Liang Rong Li ◽  
Yu Qing Chen ◽  
Zu Ming Yao ◽  
Hong Gong ◽  
...  
Keyword(s):  
Thin Films ◽  
Center Frequency ◽  
Band Pass Filter ◽  
Function Model ◽  
Modeling Tools ◽  
Pass Filter ◽  
Band Pass ◽  
Simulation Results ◽  
Weighting Methods ◽  
Piezoelectric Substrate

The design uses silicon-AlN thin films as the piezoelectric substrate, Use apo- dization weighting methods to optimize the design of IDT. The improved δ function model was Modeling Tools of Apodization weighted ellipse IDT structure, According to the result of simulation, we designed a layout of SAW band-pass filter and fabricated a sample of it which center frequency is 300MHz and insertion loss is 7dB, The research shows the consistency of simulation results with the experimental results.

Effect of RF Power on the Formation and Morphology Evolution of ZnO Nanostructured Thin Films

2012 ◽  
Vol 576 ◽  
pp. 577-581 ◽  
Author(s):  
N.D.M. Sin ◽  
Mohamad Hafiz Mamat ◽  
Mohamed Zahidi Musa ◽  
S. Ahmad ◽  
A. Abdul Aziz ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Structural Properties ◽  
Zno Thin Films ◽  
Morphology Evolution ◽  
Zno Thin Film ◽  
Rf Power ◽  
Nanostructured Thin Films ◽  
Atomic Force ◽  
Current Voltage

The effect of RF power on the formation and morphology evolution of ZnO nanostructured thin films deposited by magnetron sputtering are presented. This project focused on electrical, optical and structural properties of ZnO thin films. The effect of variation of RF power at 50 watt-250 watt at 200 °C on glass substrate of the ZnO thin films was investigated. The thin films were examined for electrical properties and optical properties using two point probe current-voltage (I-V) measurement (Keithley 2400) and UV-Vis-NIR spectrophotometer (JASCO 670) respectively. The structural properties were characterized using field emission scanning electron microscope (FESEM) (JEOL JSM 7600F) and atomic force microscope (AFM) (Park System XE-100). The IV measurement indicated that at RF power 200 watt the conductivity of ZnO thin film show the highest. All films show high UV absorption properties using UV-VIS spectrophotometer (JASCO 670). The root means square (rms) roughness for ZnO thin film were about 4 nm measured using AFM. The image form FESEM observed that transformation of structure size started to change as the RF power increase.

Design and Development of a 14-Pole High-Temperature Superconducting Filter at 127.5MHz

2013 ◽  
Vol 392 ◽  
pp. 672-675 ◽  
Author(s):  
Jian Chang Du ◽  
Lai Yun Ji ◽  
Li Juan He
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Return Loss ◽  
Band Pass Filter ◽  
Pass Filter ◽  
High Temperature Superconducting ◽  
Hts Filter ◽  
Band Pass ◽  
Temperature Test ◽  
Better Than

A high-temperature superconducting (HTS) band-pass filter centered frequency at 127.5MHz was successfully designed and developed. The HTS filter is 14-pole, adopting compact symmetrical dual-spiral resonators. The filter was fabricated on a 3-inch-diameter 0.5-mm-thick LaAlO3 wafer with double-sided DyBa2Cu3O7 thin films. Through the low temperature test, the insertion loss of the HTS filter is under 0.1dB, the bandwidth is 20 MHz, the return loss is better than-22dB and the out-of-band rejection is greater than 80dB. The filters measurements agree well with the simulation.

scholarly journals In-Lens Band-Pass Filter for Secondary Electrons in Ultrahigh Resolution SEM

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2307 ◽  
Author(s):  
Ivo Konvalina ◽  
Filip Mika ◽  
Stanislav Krátký ◽  
Eliška Materna Mikmeková ◽  
Ilona Müllerová
Keyword(s):  
Test Sample ◽  
Electron Energy Spectrum ◽  
Band Pass Filter ◽  
Energy Window ◽  
Secondary Electrons ◽  
Pass Filter ◽  
Backscattered Electrons ◽  
Band Pass ◽  
Electron Microscopes ◽  
Lift Off

Scanning electron microscopes come equipped with different types of detectors for the collection of signal electrons emitted from samples. In-lens detection systems mostly consist of several auxiliary electrodes that help electrons to travel in a direction towards the detector. This paper aims to show that a through-the-lens detector in a commercial electron microscope Magellan 400 FEG can, under specific conditions, work as an energy band-pass filter of secondary electrons that are excited by the primary beam electrons. The band-pass filter properties verify extensive simulations of secondary and backscattered electrons in a precision 3D model of a microscope. A unique test sample demonstrates the effects of the band-pass filter on final image and contrast with chromium and silver stripes on a silicon substrate, manufactured by a combination of e-beam lithography, wet etching, and lift-off technique. The ray tracing of signal electrons in a detector model predicate that the through-the-lens detector works as a band-pass filter of the secondary electrons with an energy window of about 3 eV. By moving the energy window along the secondary electron energy spectrum curve of the analyzed material, we select the energy of the secondary electrons to be detected. Energy filtration brings a change in contrast in the image as well as displaying details that are not otherwise visible.

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