Organic dielectrics

Haag R, Rampi MA, Holmlin RE, Whitesides GM (1999) Electrical breakdown of aliphatic and aromatic self-assembled monolayers used as nanometer-thick organic dielectrics. J Am Chem Soc 121(34) 7895-7906... 

The main objective of the work to be described here is to design and synthesize new organic dielectric materials, and to develop new techniques to deposit these materials as thin, thermally stable films with very low dielectric constants, for use as ILDs. New dielectric materials must not only possess proper electrical, thermal, and mechanical properties but should also minimize or eliminate the use of solvents in this era of concern for environmental pollution. 

The hquid crystalline, a-substituted quinquethiophene was used by the same group to translate this approach of self-assembly from the Si02 gate dielectric surface of FETs to assembly on organic dielectric surfaces, a first step toward fabricating flexible monolayer electronics [72]. Figure 11a provides a schematic of... 

Most organic dielectrics are usually grafted from solution, so again we will con-... 

Abstract. The paper presents results of theoretical and experimental investigations of the process of electrochemical conversion of organic dielectrics into nanosized carbon structures. A new low-temperature method for the synthesis of fractal carbon materials with micro- and nanoparticles having a fibrous, spheroidal, dendritic, and other structure has been briefly characterized. 

Nunes et al. wanted to find out whether transistors made with PHS and other organic dielectrics could show the excellent performance already reported for the pentacene transistors. This will help to determine whether other polymers with improved characteristics can be found. They investigated the effect of PHS on important device characteristics, threshold voltage and subthreshold slope. The dielectrics they investigated and their dielectric properties are shown in Fig. 6.22. Measured mobilities in transistors fabricated... 

The mechanism of the polarity inversion of tautomeric molecules is totally different from the orientation polarization of conventional organic dielectrics, such as camphor and poly(vinylidene fluoride), and the dielectric response of this new type of dielectric should be much faster. Furthermore, a significant contribution of the proton-tunnelling mechanism to the proton tautomerism is frequently observed. Consequently, the dielectric property derived from proton tautomerization should have a high chance of being related to quantum phenomena. 

The organic dielectrics known as polyimides have been studied extensively by a variety of bulk characterizational techniques as a perusal of the literature will illustrate. Little has been published on their surface properties. X-ray photoelectron spectroscopy (ESCA) has been extremely useful for polymer characterization (, 7, ), In a previous paper ( ), we have reported the ESCA spectra of structurally different polyimides derived from both commercially available polyamic acid resins (DuPont s PI5878, PI2525, PI2550), and from laboratory synthesized polyamic acid resins. 

Organic Dielectric Materials with Reduced Moisture Absorption and Improved Electrical Properties... 

GOFF ET AL. Organic Dielectric Materials with Improved Properties... 

A disadvantage of all organic dielectrics is the decreased thermal conductivity, which may result in localized overheating. Purity is another concern. 

Dielectric Loss If an organic dielectric is incorporated into an a.c. line the heat generated by dielectric loss in this material must be included in the operating costs. Unfortunately most polymers are poor dielectrics (have relatively large loss tangents) at low temperatures so this term can be comparable to the superconductor loss for lines operating near 4.2 K. 

V. I. Arkhipov, E. V. Emelianova, and H. Bassler. Charge carrier transport and recombination at the interface between disordered organic dielectrics. /. Appl. 

The first attempts to deposit organic dielectrics as surface films onto glass substrates were stimulated by Langmuir s observation [50] that some substances of high molecular weight insoluble in water and also having polar groups spread over a water surface as a monomolecular layer could be transferred to the surface of a solid... 

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