Generation of very high‐frequency ultrasonic waves using thin films of vinylidene fluoride‐trifluoroethylene copolymer

1987 ◽  
Vol 61 (10) ◽  
pp. 4749-4754 ◽  
Author(s):  
Kuniko Kimura ◽  
Hiroji Ohigashi
Keyword(s):  
Thin Films ◽  
High Frequency ◽  
Vinylidene Fluoride ◽  
Ultrasonic Waves ◽  
Very High Frequency ◽  
Very High

scholarly journals Measurement of Electrical Properties of Superconducting YBCO Thin Films in the VHF Range

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3360
Author(s):  
Yakir Dahan ◽  
Eldad Holdengreber ◽  
Elichai Glassner ◽  
Oz Sorkin ◽  
Shmuel E. Schacham ◽  
...  
Keyword(s):  
Thin Films ◽  
Theoretical Model ◽  
Quality Factor ◽  
High Frequency ◽  
Unit Length ◽  
Superconducting Thin Films ◽  
Electrical Parameters ◽  
Very High Frequency ◽  
Production Constraints ◽  
Very High

A new measurement technique of electrical parameters of superconducting thin films at the Very High Frequency (VHF) range is described, based on resonators with microstrip (MS) structures. The design of an optimal resonator was achieved, based on a thorough theoretical analysis, which is required for derivation of the exact configuration of the MS. A theoretical model is presented, from which an expression for the attenuation of a MS line can be derived. Accordingly, simulations were performed, and an optimal resonator for the VHF range was designed and implemented. Production constraints of YBa2Cu3O7 (YBCO) limited the diameter of the sapphire substrate to 3″. Therefore, a meander configuration was formed to fit the long λ/4 MS line on the wafer. By measuring the complex input reflection coefficients of a λ/4 resonator, we extracted the quality factor, which is mainly affected by the dielectric and conductor attenuations. The experimental results are well fitted by the theoretical model. The dielectric attenuation was calculated using the quasi-static analysis of the MS line. An identical copper resonator was produced and measured to compare the properties of the YBCO resonator in reference to the copper one. A quality factor of ~6·105 was calculated for the YBCO resonator, three orders of magnitude larger than that of the copper resonator. The attenuation per unit length of the YBCO layer was smaller by more than five orders of magnitude than that of the copper.

Low power density multihole cathode very-high-frequency plasma for mixed phase Si:H thin films

2008 ◽  
Vol 93 (19) ◽  
pp. 191502 ◽  
Author(s):  
C. Jariwala ◽  
A. Chainani ◽  
R. Eguchi ◽  
M. Matsunami ◽  
S. Shin ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Power ◽  
Power Density ◽  
High Frequency ◽  
Mixed Phase ◽  
Very High Frequency ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Very High

Effect of deposition rate on the growth mechanism of microcrystalline silicon thin films using very high frequency PECVD

Optik ◽  
2019 ◽  
Vol 180 ◽  
pp. 104-112 ◽  
Author(s):  
Xinli Li ◽  
Ruimin Jin ◽  
Lihua Li ◽  
Jingxiao Lu ◽  
Yongjun Gu ◽  
...  
Keyword(s):  
Thin Films ◽  
Deposition Rate ◽  
Growth Mechanism ◽  
High Frequency ◽  
Microcrystalline Silicon ◽  
Very High Frequency ◽  
Silicon Thin Films ◽  
Very High

scholarly journals Diffraction of Light by Very High Frequency Ultrasonic Waves

Nature ◽  
1948 ◽  
Vol 161 (4102) ◽  
pp. 927-927 ◽  
Author(s):  
S. BHAGAVANTAM ◽  
B. RAMACHANDRA RAO
Keyword(s):  
High Frequency ◽  
Ultrasonic Waves ◽  
Very High Frequency ◽  
Diffraction Of Light ◽  
Very High

Characteristics of Cobalt Thin Films Deposited by Very High Frequency Plasma Enhanced Atomic Layer Deposition (60 and 100 MHz) Using Cobaltocene (Co(Cp)2)/NH3

2021 ◽  
Vol 21 (3) ◽  
pp. 1826-1832
Author(s):  
Won Gyun Yeom ◽  
Chang Hoon Song ◽  
Chul Hee Cho ◽  
Shin Jae You ◽  
Geun Young Yeom
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
High Frequency ◽  
Atomic Layer ◽  
Very High Frequency ◽  
Carbon Impurity ◽  
Cobalt Films ◽  
Layer Deposition ◽  
Cobalt Thin Films ◽  
Very High

In this study, cobalt films were deposited by plasma enhanced atomic layer deposition (PEALD) with cobaltocene (Co(Cp)2) using two different very high frequency (VHF) NH3 plasmas (60 MHz, 100 MHz), and the effect of different frequencies of VHF on the characteristics of NH3 plasmas and the properties of cobalt films were investigated. It is found that the higher frequency showed the higher plasma density at the same input power and, the NH radicals, which are required to remove the ligands of the cobalt precursor during the plasma exposure step in the ALD cycle, were higher at 100 MHz than those at 60 MHz. The RMS surface roughness and carbon impurity percentage of the deposited cobalt films were lower at the higher frequency possibly indicating denser films due to more active surface reactions at the higher frequency. As a result, it is expected that the cobalt thin films deposited by the higher VHF PEALD will improve the characteristics of deposited thin films.

Structural, Optical and Electrical Properties of μc-Si:H Very Thin Films Deposited by the VHF-GD Technique

1994 ◽  
Vol 336 ◽  
Author(s):  
Roger Flückiger ◽  
J. Meier ◽  
A. Shah ◽  
A. Catana ◽  
M. Brunel ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
High Frequency ◽  
Grazing Angle ◽  
Columnar Structure ◽  
Diffraction Reflection ◽  
X Ray Diffraction ◽  
Very High Frequency ◽  
X Ray ◽  
Very High

ABSTRACTIn this paper we present new results for very thin <p> μc-Si:H films (< 350 Å) deposited at low temperature (170 C) by the Very High Frequency - Glow Discharge technique (VHF-GD) at 70 MHz. First, the effect of boron doping on the growth and electrical properties of μc-Si:H very thin films is investigated, leading to an optimised value of about 0.6 % (B2H6/SiH4). Structural properties of an optimised thickness series ranging from 100 to 350 Å are studied using TEM, Raman, grazing angle X-ray diffraction/reflection and spectroscopie ellipsometry. Further, a columnar structure growth model for these very thin <p>-type μc-Si:H films will be proposed.

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