scholarly journals Development of a High-Resolution Acoustic Sensor Based on ZnO Film Deposited by the RF Magnetron Sputtering Method

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6870
Author(s):  
Dong-Chan Kang ◽  
Jeong-Nyeon Kim ◽  
Ik-Keun Park

In the study, an acoustic sensor for a high-resolution acoustic microscope was fabricated using zinc oxide (ZnO) piezoelectric ceramics. The c-cut sapphire was processed into a lens shape to deposit a ZnO film using radio frequency (RF) magnetron sputtering, and an upper and a lower electrode were deposited using E-beam evaporation. The electrode was a Au thin film, and a Ti thin film was used as an adhesion layer. The surface microstructure of the ZnO film was observed using a scanning electron microscope (SEM), the thickness of the film was measured using a focused ion beam (FIB) for piezoelectric ceramics deposited on the sapphire wafer, and the thickness of ZnO was measured to be 4.87 μm. As a result of analyzing the crystal growth plane using X-ray diffraction (XRD) analysis, it was confirmed that the piezoelectric characteristics were grown to the (0002) plane. The sensor fabricated in this study had a center frequency of 352 MHz. The bandwidth indicates the range of upper (375 MHz) and lower (328 MHz) frequencies at the −6 dB level of the center frequency. As a result of image analysis using the resolution chart, the resolution was about 1 μm.

2007 ◽  
Vol 336-338 ◽  
pp. 567-570
Author(s):  
Chong Mu Lee ◽  
Anna Park ◽  
Young Joon Cho ◽  
Hyoun Woo Kim ◽  
Jae Gab Lee

It is very desirable to grow ZnO epitaxial films on Si substrates since Si wafers with a high quality is available and their prices are quite low. Nevertheless, it is not easy to grow ZnO films epitaxially on Si substrates directly because of formation of an amorphous SiO2 layer at the interface of ZnO and Si. A Zn film and an undoped ZnO film were deposited sequentially on an (100) Si substrate by rf magnetron sputtering. The sample was annealed at 700°C in a nitrogen atmosphere. X-ray diffraction (XRD), photoluminescence (PL) and atomic force microscopy (AFM) analyses were performed to investigate the cristallinity and surface morphology of the ZnO film. According to the analysis results the crystallinity of a ZnO thin film deposited by rf magnetron sputtering is substantially improved by using a Zn buffer layer. The highest ZnO film quality is obtained with a 110nm thick Zn buffer layer. The surface roughness of the ZnO thin film increases as the Zn buffer layer thickness increases.


2021 ◽  
Vol 127 (7) ◽  
Author(s):  
Du-Cheng Tsai ◽  
Feng-Kuan Chen ◽  
Zue-Chin Chang ◽  
Bing-Hau Kuo ◽  
Erh-Chiang Chen ◽  
...  

2017 ◽  
Vol 86 (7) ◽  
pp. 074704 ◽  
Author(s):  
Wataru Namiki ◽  
Takashi Tsuchiya ◽  
Makoto Takayanagi ◽  
Shoto Furuichi ◽  
Makoto Minohara ◽  
...  

2014 ◽  
Vol 601 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Kyong Chan Heo ◽  
Phil Kook Son ◽  
Youngku Sohn ◽  
Jonghoon Yi ◽  
Jin Hyuk Kwon ◽  
...  

2011 ◽  
Vol 257 (6) ◽  
pp. 2134-2141 ◽  
Author(s):  
K. Elayaraja ◽  
M.I. Ahymah Joshy ◽  
R.V. Suganthi ◽  
S. Narayana Kalkura ◽  
M. Palanichamy ◽  
...  

2007 ◽  
Vol 1035 ◽  
Author(s):  
Seol Hee Choi ◽  
Chan Hyoung Kang

AbstractHighly c-axis oriented, dense, and fine-grained polycrystalline ZnO films with smooth surface and high resistivity were deposited on 4 inch silicon wafers by employing ZnO targets in a radio-frequency (RF) magnetron sputtering system. By changing applied RF power, substrate temperature and O2/Ar gas ratio, the optimum process parameters were found to be 150 W, 200 °C and 30/70, respectively. Applying the ZnO films deposited under these optimum conditions, surface acoustic wave (SAW) devices of ZnO/IDT/SiO2/Si structure were fabricated by conventional photolithography and etching processes. The interdigital transducers (IDT), made of the aluminum deposited by DC magnetron sputter, were patterned as 2.5/2.5 μm of finger width/spacing. Another type of SAW filter of IDT/ZnO/diamond/Si structure was fabricated. In this structure, high-quality nanocrystalline diamond (NCD) films were deposited on 4 inch silicon wafers by direct current (DC) plasma assisted chemical vapor deposition method using H2-CH4 mixture as precursor gas. On the top of the diamond films, ZnO films were deposited under the optimum conditions. The aluminum IDT pattern was fabricated on the ZnO/diamond layered films. The characteristics of the fabricated SAW devices were evaluated in terms of center frequency, insertion loss, and wave propagation velocity.


2003 ◽  
Vol 82 (7) ◽  
pp. 1117-1119 ◽  
Author(s):  
P. F. Carcia ◽  
R. S. McLean ◽  
M. H. Reilly ◽  
G. Nunes

2013 ◽  
Vol 27 (22) ◽  
pp. 1350156 ◽  
Author(s):  
R. J. ZHU ◽  
Y. REN ◽  
L. Q. GENG ◽  
T. CHEN ◽  
L. X. LI ◽  
...  

Amorphous V 2 O 5, LiPON and Li 2 Mn 2 O 4 thin films were fabricated by RF magnetron sputtering methods and the morphology of thin films were characterized by scanning electron microscopy. Then with these three materials deposited as the anode, solid electrolyte, cathode, and vanadium as current collector, a rocking-chair type of all-solid-state thin-film-type Lithium-ion rechargeable battery was prepared by using the same sputtering parameters on stainless steel substrates. Electrochemical studies show that the thin film battery has a good charge–discharge characteristic in the voltage range of 0.3–3.5 V, and after 30 cycles the cell performance turned to become stabilized with the charge capacity of 9 μAh/cm2, and capacity loss of single-cycle of about 0.2%. At the same time, due to electronic conductivity of the electrolyte film, self-discharge may exist, resulting in approximately 96.6% Coulombic efficiency.


Sign in / Sign up

Export Citation Format

Share Document