Experimental and Theoretical Study of AC Electrical Conduction Mechanisms of Semicrystalline Parylene C Thin Films

Abstract

The electrical conduction mechanisms of semicrystalline thermoplastic parylene C (-H(2)C-C(6)H(3)Cl-CH(2)-)(n) thin films were studied in large temperature and frequency regions. The alternative current (AC) electrical conduction in parylene C is governed by two processes which can be ascribed to a hopping transport mechanism: correlated barrier hopping (CBH) model at low [77-155 K] and high [473-533 K] temperature and the small polaron tunneling mechanism (SPTM) from 193 to 413 K within the framework of the universal law of dielectric response. The conduction mechanism is explained with the help of Elliot's theory, and the Elliot's parameters are determined. From frequency- and temperature-conductivity characteristics, the activation energy is found to be 1.27 eV for direct current (DC) conduction interpreted in terms of ionic conduction mechanism. The power law dependence of AC conductivity is interpreted in terms of electron hopping with a density N(E(F)) (~10(18) eV cm(-3)) over a 0.023-0.03 eV high barrier across a distance of 1.46-1.54 Å.

Alternative current conduction mechanisms of organic-inorganic compound [N(CH3)3H]2CuCl4

“…We note that "U eff " decreases with the increase in the frequency, this result is in good agreement with the literature. 42 This trend is in accord with the electronic conduction by hopping for these ranges of frequency and temperature. Indeed, while considering this mode of conduction, the increase in the application frequency of the electric field will support the electronic jumps amongst the localized states, which will be translated into energy U eff by a lowering of the value.…”

“…We observe the augmentation of both parameters a and N (E F ) with frequency, which is in accord with the literature. 42,44 The reasonably high values of N (E F ) ($10 27 eV À1 cm À3 ) suggest that the hopping between the pairs of sites dominates the mechanism of charge transport in the [N(CH 3 ) 3 H] 2 CuCl 4 hybrid compound. 44 The values of the tuning distance (R x ) determined from Eq.…”

Determination of density of defect states in glassy Se 98 M 2 (M = Ag, Cd and Sn) alloys using a.c. conductivity measurements

“…In this situation, the curve cannot be extended to high temperature range because there will be a dielectric loss peak at the frequency x m . [18,30]. The value of x m is given by the following relation:…”

Effect of film thickness on structural, morphology, dielectric and electrical properties of parylene C films

“…[24][25][26] One of the most important applications of parylene thin films is used as the inter-level dielectric insulators within largescale integration (LSI). In this case, the parylene thin films must have low dielectric constant and high electric resistance, so the measurement of the electrical properties for parylene thin films is a necessary technology.…”