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Date submitted2017-11-15
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Date accepted2018-01-13
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Date published2018-04-24
Use of nano-dimensional hydrophobic coatings for obtaining electrets based on silicon dioxide
- Authors:
- N. S. Pshchelko
The article considers the physical-technological foundations of formation of the silicon dioxide (SiO 2 ) based electret for use in devices of MEMS technology. Studies have shown that the best electret properties are in SiO 2 obtained in «wet» oxygen medium as compared to samples obtained by other oxidation methods. This is probably due to the large number of Si-OH groups on the surface of the oxide in the «wet» SiO 2 , which increases the effectiveness of the hydrophobic coatings during the modification of the SiO 2 surface. It has been found that other methods of obtaining oxide, for example, electrochemical or plasmachemical, do not make it possible to obtain SiO 2 with good electret properties. The decrease of the charge injected into an electret can occur due to the presence of volume or surface conductivity, as well as the screening of this charge by opposite charges from the medium, leading to significant decrease of electret surface potential at high ambient humidity. To increase the stability of the electret effect, it is necessary to perform water-repellency treatment of SiO 2 surface by applying thin (nanosized) water-repellent coatings. Experimental results on the stability of the electret surface potential are presented for usage of various water repellents. The most promising water repellents are high-temperature photoresist FPT-1-40 and polyimide nanolayer compositions – Langmuir-Blodgett films.
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Date submitted2009-09-21
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Date accepted2009-11-11
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Date published2010-06-25
Procedure for determination of parameters of a condesing structures with a movable capacitor plates
- Authors:
- N. S. Pshchelko
Procedure for definition of parameters of a condenser structure cap is considered. The procedure allows by means of one operation – volt – capacitance characteristic measuring – to define the whole complex of the major parameters of a cap – size of a working air gap, a membrane deflection, surface electret potential and a membrane tension. The expressions for capacitance of a condenser structure cap as a function of specified parameters are obtained. Analytical expression for capacitance of a cap depending on the specified parameters and measuring of its volt-capacitance characteristic allow to define these parameters by solving corresponding system of equations. The procedure considered in the present work is a not-destroying quality monitoring method.
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Date submitted2009-09-26
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Date accepted2009-11-22
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Date published2010-06-25
Use of mosfet for the control of dielectric characteristics
- Authors:
- N. S. Pshchelko
- A. S. Mustafaev
In this work a device for measurement on a constant voltage of the basic electric characteristics of high-resistance dielectric materials and products from – their electric capacitance and resistance – is developed. The principle of work of the device is based on use of transients in connected in sereies elements having electric capacity and resistance. In the electric circuit of the device the MOSFET with high entrance resistance is used. The device on the basis of the MOSFET for measurement of surface potential of dielectrics is considered also. Use of this device is especially effective at measurement of electret surface potential. Results of research of electrets on a basis of silicon dioxide are discussed.