Silicondioxide electret films prepared by the sol-gel process

Abstract

Sol-gel silica electret films were coated on silicon substrates b y a spin coating technique. The process of preparing the Alms is described and the electret behavior of the films is discussed. The films were corona charged at room temperature. Then, isothermal decay of the surface potential at room temperature and open-circuit thermally stimulated discharge ( T S D ) experiments were carried out. The results showed that the main p e a k of the TSD current spectra was situated at -250'C and charge deposited in the film indicated good stability for the negative charged sample. After storage at room temperature for 50 days, the surface potential of the sample still retained at -90% of the initial value. We f o u n d activation energies of 1.3 and 0.7 eV for negative and positive corona charged samples. O u r experimental results suggest that the sol-gel process could be useful in electret and electronic technique applications.

High surface-charge stability of porous polytetrafluoroethylene electret films at room and elevated temperatures

“…For higher charging temperatures, roughly the same amount of charge (open-circuit TSD is semi-quantitative if the sample geometry is reproduced sufficiently well) is preferentially found in traps that release charge only at higher temperatures (above approximately 200 • C for charging at 150 or 200 • C). A similar behaviour was also found for negative charging of porous PTFE if the higher TSD-peak temperatures expected for negatively charged samples are taken into account [6].…”

Surface modified spin-on xerogel films as interlayer dielectrics

“…Several authors [5][6][7][8] have reported the successful deposition of spin-coated silica sol-gel films. Hrubesh and Poco 5 used supercritical drying to form aerogel films, while the others 6-8 formed densified sol-gel films that had extremely low porosities.…”

Effects of varying the through silicon via liners thickness on their hoop stresses and deflections

“…However, some research work has been done on other materials which have some advantages not found in silicon dioxide or different forms of it. Research work [13] discussed that in the past several years, the inorganic dielectric formed by sol–gel process was studied extensively by the researchers [13, 14] as a potential substitution of the conventional thermally wet grown SiO 2 because of its technological interest. The technique was not only cheap and needed processing at high temperature for a shorter time but also only a small amount of raw materials was needed.…”