ZnO Based SAW Delay Line: Thin Film Characteristics and IDT Fabrication

2003 ◽  
Vol 785 ◽  
Author(s):  
Farid Hassani ◽  
Shahrokh Ahmadi ◽  
Can E. Korman ◽  
Mona Zaghloul ◽  
Shiva Hullavarad ◽  
...  

AbstractZnO, a well-known piezoelectric material, is used to develop micro-scale Surface Acoustic Wave (SAW) delay line sensor. In this work, SAW delay line Devices are fabricated employing ZnO films that are deposited by RF sputtering technique. Films are characterized prior to device fabrication by X-Ray Diffraction (XRD) for film crystalline quality, UV-visible transmission spectroscopy for optical characteristics, and Atomic Force Microscopy (AFM) for surface morphology. Interdigital electrodes producing surface acoustic waves in the hundreds of MHz are developed by photolithography and metalization techniques. SAW delay line device testing, measurement and characteristics on RF sputtered ZnO films are presented and compared.

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4250-4254 ◽  
Author(s):  
JIAN-GUO LU ◽  
ZHI-ZHEN YE ◽  
HAN-HONG CHEN ◽  
JING-YUN HUANG ◽  
BING-HUI ZHAO

ZnO films with (100) preferred orientation are reported for the first time. ZnO films were synthesized on Si(100) substrate by solid-source chemical vapor deposition (SS-CVD) using zinc acetate dihydrate (solid) as a precursor. The structural properties were investigated by X-ray diffraction and atomic force microscopy. Results show that a lower growth temperature and a higher deposition rate will facilitate the formation of (100) texture. The texture coefficient for (100) plane is 3.28.


1996 ◽  
Vol 449 ◽  
Author(s):  
A. J. Drehman ◽  
P. W. Yip

ABSTRACTUsing reactive rf sputtering, we have grown (0001) oriented ZnO films in situ on heated c-axis sapphire substrates, that are promising, particularly in terms of surface roughness, as buffer layers for the subsequent epitaxial growth of III-V nitride films. We compare the effects of on-axis and off-axis sputter geometries on the film epitaxy and smoothness. We also examined the effect of substrate temperature on the growth and smoothness and quality of the film. X-ray diffraction was used to verify the hexagonal ZnO phase, its c-axis orientation and, qualitatively, the degree of its epitaxy. Atomic Force Microscopy (AFM) was used to determine the ZnO growth morphology and roughness. Our best films, obtained by off-axis sputter deposition, have a surface roughness of less than 1 nm.


2020 ◽  
Vol 38 (2) ◽  
pp. 328-333
Author(s):  
Kimia Nikpasand ◽  
Seyed Mohammad Elahi ◽  
Amir Hossein SarI ◽  
Arash Boochani

AbstractCopper (Cu) and nickel (Ni) nanoparticles have been grown simultaneously on glass and silicon substrates by RF sputtering method to form three Cu/Ni nanocomposites at different deposition times. The existence of Cu and Ni peaks in the X-ray diffraction (XRD) profiles confirms the crystalline structure of samples with Cu and Ni atomic content which have also been characterized by Rutherford backscattering (RBS) method. Moreover, the structural and morphological properties of the prepared nanocomposites have been compared with respect to their morphologies by means of atomic force microscopy (AFM) analysis. In order to compare the surface roughness over different spatial frequency ranges and evaluate surface quality, power spectral density (PSD) of each sample has been extracted from AFM data and also, the experimental and theoretical results have been compared. The fractal nature of these nanocomposites has been finally discussed.


1998 ◽  
Vol 13 (5) ◽  
pp. 1318-1326 ◽  
Author(s):  
P. C. Liao ◽  
W. S. Ho ◽  
Y. S. Huang ◽  
K. K. Tiong

Iridium dioxide (IrO2) thin films, deposited on Si substrates by reactive rf sputtering method under various conditions, were characterized by atomic force microscopy (AFM), x-ray diffraction (XRD), electrical-conductivity, spectrophotometry, ellipsometry and Raman scattering measurements. The average grain sizes of the films were estimated by AFM. A grain boundary scattering model was used to fit the relation between the average grain size and electrical resistivity. The optical and dielectric constants were determined by the ellipsometry measurements. The results of the electrical and optical studies show a metallic character of the films deposited at higher temperatures. The results of XRD and Raman scattering indicate that the IrO2 films deposited at temperatures higher than 300 °C show the presence of (200) texture.


2003 ◽  
Vol 18 (3) ◽  
pp. 545-548 ◽  
Author(s):  
Parmanand Sharma ◽  
Sanjeev Kumar ◽  
K. Sreenivas

The frequency response of a 37 MHz bulk LiNbO3 surface acoustic wave (SAW) filter with a 200-nm-thick ZnO overlayer exhibited a downshift in the frequency with ultraviolet (UV) light due to acoustoelectric interactions between the photo-generated carriers in the semiconducting ZnO and the surface acoustic waves. In contrast, a 36 MHz ZnO thin film SAW delay-line with insulating ZnO films exhibited an upshift in the frequency. The response was more pronounced at higher harmonics (130–315 MHz) and was attributed to changes in the elastic/dielectric properties in the upper surface layer of ZnO. A linear change in the frequency with UV intensity shows immense applicability for wireless ultraviolet sensor applications.


2020 ◽  
Vol 19 (03) ◽  
pp. 1950022
Author(s):  
S. Jainulabdeen ◽  
C. Gopinathan ◽  
A. Mumtaz Parveen ◽  
K. Mahalakshmi ◽  
K. Jeyadheepan ◽  
...  

Rod-structured ZnO has grown hydrothermally on the seed layer by varying growth time. The growth mechanism of rod-structured ZnO thin films is studied extensively with the help of characterizing tools. The preferred orientation and c/a ratio are studied with Grazing Incidence X-ray diffraction (GIXRD). The growth mechanism of ZnO rod structure is studied in detailed manner with Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM). The optical absorption and emission properties of ZnO rods are studied with respect to growth morphology. Ethanol sensing measurements are carried out at room temperature (RT). The nanostructured ZnO films show good response and sensitivity to ethanol gas at RT.


2015 ◽  
Vol 1766 ◽  
pp. 167-177 ◽  
Author(s):  
L. Khomenkova ◽  
V. Kushnirenko ◽  
M. Osipenok ◽  
K. Avramenko ◽  
Y. Polishchuk ◽  
...  

ABSTRACTUndoped and Li-doped ZnO films were fabricated by screen printing approach on sapphire substrate. The effect of Li doping and annealing temperature on the luminescent, optical, electrical and structural properties of the films has been investigated by the photoluminescence (PL), Raman scattering, conductivity, Atomic Force microscopy and X-ray diffraction (XRD) methods. The XRD study revealed that the films have polycrystalline wurtzite structure with grain sizes ranging from 26 to 38 nm. In the undoped ZnO films, the increase of annealing temperature from 800 to 1000 °C resulted in the increase of the grain sizes, film conductivity and the intensity of the ultraviolet PL. The introduction of Li of low concentration of 0.003 wt % at 800 °C or 900 °C allows producing the low-resistive films with enhanced ultraviolet PL and reduced density of crystalline defects. Highly doped films (with 0.3 wt % of Li) were found to be semi-insulating with deteriorated PL properties irrespectively of the annealing temperature. It is shown that introduction of Li in the ZnO films affects their PL spectra mainly via the evolution of the film crystallinity and the density of intrinsic defects.


2021 ◽  
Author(s):  
Taner Kutlu ◽  
Necdet H. Erdogan ◽  
Nazmi Sedefoglu ◽  
Hamide Kavak

Abstract This study reports the effect of annealing temperature on the structural, morphological, and optical properties of ZnO (Zinc Oxide) thin films deposited on a glass substrate by the sol-gel spin coating method. Those properties of ZnO were examined with UV-Vis, Fourier transform infrared (FTIR) and Raman spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and X-ray diffraction (XRD), before and after annealing. XRD results revealed that all the samples had a highly c-axis oriented wurtzite structure. A 1 (LO) mode in Raman spectra also confirmed the highly oriented ZnO films. Optical measurement indicated that transmittance of the films was above %85, and the optical band gap slightly decreased with the increasing annealing temperature from 350 to 550 °C. Morphological analysis displayed that increasing annealing temperature improved surface morphology and enlarged the grain size from 2-3 nm for as-deposited samples to 150 nm for annealed at 550 °C.


2021 ◽  
Vol 118 (3) ◽  
pp. 031602
Author(s):  
Brian Douglas Rummel ◽  
Leonid Miroshnik ◽  
Marios Patriotis ◽  
Andrew Li ◽  
Talid R. Sinno ◽  
...  

2013 ◽  
Vol 307 ◽  
pp. 333-336
Author(s):  
Shiuh Chuan Her ◽  
Tsung Chi Chi

Zinc oxide (ZnO) thin films were deposited on glass substrate by Radio frequency (RF) magnetron sputtering. The effect of substrate temperature on the microstructure of the ZnO films has been investigated. Crystal structure and surface morphology of the films were examined by X-ray diffraction (XRD) and atomic force microscopy (AFM). XRD patterns and AFM images show that the crystallinity and grain size are increasing with the increase of substrate temperature.


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