Capacitances, interlayer

Low Interlayer Capacitance. A multilevel structure consisting of a metal-dlelectric-metal sandwich is a capacitor whose capacitance is determined by the dielectric constant and total charge of the dielectric. 

For future high-speed microelectronic devices, copper interconnection with low dielectric constant (low-k) interlayer films is required to decrease RC (R interconnect resistance, C interlayer dielectric capacitance) delay. Recently, porous Si02 and silica-based films, developed for low-k films, have been extensively studied by positron annihilation spectroscopy [28], [29], [19]. Since Ps formation occurs with high probability, and the o-Ps annihilate via pick-off process in Si02-based materials, positron annihilation spectroscopy (especially PALS) gives useful information on the size of the pores. 

It follows from the calculations (Figs. 34 and 35) that at low frequencies, a divergence arises in the effective dielectric constant and in the effective conductivity (a sharp increase in losses). This is explained by the fact that finite clusters of the metallic phase now arise in the system which are separated by thin insulating interlayers. Such structures form a hierarchical self-similar chaotic capacitance net that generates a system of resonance frequencies. 

Capacitive interference, the signal delay caused by the permittivity of insulating layers, the minimum required interlayer dielectric thicknesses, and the power dissipation, can all be decreased by designing polymers with lower values of e. The synthesis of polymers which simultaneously have low values of and outstanding thermal and mechanical properties is therefore crucial for applications in the electronics industry. 

An example of this approach is represented by the growth of 3-D coordination polymers with SCO properties via stepwise adsorption reactions for multilayer films based entirely on intra- and interlayer coordination bonds Fe(pyrazine) [Pt(CN) ] [218, 219], Indeed, after functionalization of the surface with the appropriate anchoring layer the coordination polymer is built in a stepwise fashion, alternating the metal ion (Fe "), the platinum salt ([Pt(CN) ] ), and pyrazine. The polymer shows many interesting properties, with the SCO transition accompanied by a variation in the dielectric constant of the material accompanied by a room temperature hysteresis of the dielectric constants. This dielectric hysteretic property may be useful in building molecular memory devices that can store information by high- and low-capacitance states. What must be remarked here is that these appealing properties cannot be exploited in bulk materials, but only in thin films. 

Design options to reduce the interlayer capacitance of solenoid coils. 

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