Plasma‐Polymerized Multistacked Organic Bipolar Films: A New Approach to Flexible High‐κ Dielectrics

Abstract

Organic-based flexible dielectric films with high permittivity (e) are desirable for future applications of organic thin-film transistors, such as smartcards and radio frequency identification (RFID) tags, that concurrently desire flexible or conformable substrates. Advances in the development of all-polymer field-effect transistors (PFETs) have been particularly significant for their potential in a flexible form. Major improvements have been reported for both the semiconductor and the dielectric components of PFETs. For example, with respect to semiconductor considerations, noteworthy gains have been achieved in increasing carrier mobility and in identifying lower-cost production technology, however, PFET operational voltages tend to be too high for the intended portable applications. But the voltages could be significantly lowered if a suitable dielectric with a high dielectric constant (k), compatible with the PFET process and in a flexible form factor with thicknesses that is controllably thin, was identified. This Communication focuses on the organic dielectric film component of PFETs, required for all-polymer PFETs by tailoring high-k polymer films. The much-needed advances in this area pose difficult challenges in terms of materials science considerations. One such problem centers on the fact that organic films are inherently low-k; having k values significantly less than those of ceramic (inorganic) materials. Additionally, leakage currents through the film also pose potential problems given the generally porous nature of organic based polymeric films. On the other hand, organic films offer far more favorable